出版社 SPRINGER

Cover for Dieter Schinzer · Selectivities in Lewis Acid Promoted Reactions - NATO Science Series C (Hardcover Book) [1989 edition] (1989)

Selectivities in Lewis Acid Prom... (1989)

Dieter Schinzer

Cover for T.L. White · Predicting Breeding Values with Applications in Forest Tree Improvement - Forestry Sciences (Hardcover Book) [1989 edition] (1989)

Predicting Breeding Values with ... (1989)

Cover for Archibugi, Franco, Professor · Economy & Ecology: Towards Sustainable Development - Economy & Environment (Hardcover Book) [1989 edition] (1989)

Economy & Ecology: Towards Susta... (1989)

Archibugi, Franco, Professor

Cover for D. De Moulin · A short history of breast cancer (Paperback Book) [Softcover reprint of the original 1st ed. 1989 edition] (1989)

Softcover reprint of the original 1st ed. 1989 edition

A short history of breast cancer (1989)

Cover for Donna M Mertens · Creative Ideas For Teaching Evaluation: Activities, Assignments and Resources - Evaluation in Education and Human Services (Hardcover Book) [1989 edition] (1989)

Creative Ideas For Teaching Eval... (1989)

Donna M Mertens

Cover for Richard Szeliski · Bayesian Modeling of Uncertainty in Low-Level Vision - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1989 edition] (1989)

Bayesian Modeling of Uncertainty... (1989)

Richard Szeliski

Cover for Jerry B Ayers · A Practical Guide to Teacher Education Evaluation - Evaluation in Education and Human Services (Hardcover Book) [1989 edition] (1989)

A Practical Guide to Teacher Edu... (1989)

Cover for George Heffernan · Isagoge in Die Phanomenologische Apophantick (Hardcover Book) [1989 edition] (1989)

Isagoge in Die Phanomenologische... (1989)

George Heffernan

Cover for Hamelmann H. · Verhandlungen Der Deutschen Gesellschaf (Paperback Book) (1989)

Verhandlungen Der Deutschen Gese... (1989)

Cover for Helmut Kaufer · Cad-expertensystem: Kunststoff Metall Kleben (Paperback Book) (1989)

Cad-expertensystem: Kunststoff M... (1989)

Cover for N. S. Bakhvalov · Homogenisation: Averaging Processes in Periodic Media: Mathematical Problems in the Mechanics of Composite Materials - Mathematics and its Applications (Hardcover Book) [1989 edition] (1989)

Homogenisation: Averaging Proces... (1989)

N. S. Bakhvalov

Cover for James Robert Brown · An Intimate Relation: Studies in the History and Philosophy of Science Presented to Robert E. Butts on his 60th Birthday - Boston Studies in the Philosophy and History of Science (Hardcover Book) [1989 edition] (1989)

An Intimate Relation: Studies in... (1989)

James Robert Brown

Cover for A. Ya Helemskii · The Homology of Banach and Topological Algebras - Mathematics and its Applications (Hardcover Book) [1989 edition] (1989)

The Homology of Banach and Topol... (1989)

A. Ya Helemskii

Cover for Robert E Butts · Constructivism and Science: Essays in Recent German Philosophy - The Western Ontario Series in Philosophy of Science (Hardcover Book) [1989 edition] (1989)

Constructivism and Science: Essa... (1989)

Cover for G F Bassani · Progress in Electron Properties of Solids: Festschrift in honour of Franco Bassani - Physics and Chemistry of Materials with Low-Dimensional Structures (Hardcover Book) [1989 edition] (1989)

Progress in Electron Properties ... (1989)

Cover for C.T. Sistare · Responsibility and Criminal Liability - Law and Philosophy Library (Hardcover Book) [1989 edition] (1989)

Responsibility and Criminal Liab... (1989)

Cover for V Tejera · History and Anti-History in Philosophy - Nijhoff International Philosophy Series (Hardcover Book) [1989 edition] (1989)

History and Anti-History in Phil... (1989)

Cover for P.g Aaron · Reading and Writing Disorders in Different Orthographic Systems - NATO Science Series D: (Hardcover Book) [1989 edition] (1989)

Reading and Writing Disorders in... (1989)

Cover for J. Rouwendal · Choice and Allocation Models for the Housing Market - Studies in Operational Regional Science (Hardcover Book) [1989 edition] (1989)

Choice and Allocation Models for... (1989)

Cover for International Association for Research in Economic Psychology · Understanding Economic Behaviour - Theory and Decision Library A: (Hardcover Book) [1989 edition] (1989)

Understanding Economic Behaviour... (1989)

International Association for Re...

Cover for J Vos · Effects of Crop Rotation on Potato Production in the Temperate Zones: Proceedings of the International Conference on Effects of Crop Rotation on Potato Production in the Temperate Zones, held August 14-19, 1988, Wageningen, The Netherlands - Developments (Hardcover Book) [1989 edition] (1989)

Effects of Crop Rotation on Pota... (1989)

Cover for Menas Karatos · Bell's Theorem, Quantum Theory and Conceptions of the Universe - Fundamental Theories of Physics (Hardcover Book) [1989 edition] (1989)

Bell's Theorem, Quantum Theory a... (1989)

Cover for International Association for Breast Cancer Research · Breast Cancer: Progress in Biology, Clinical Management and Prevention: Proceedings of the International Association for Breast Cancer Research Conference, Tel-Aviv, Isreal, March 1989 - Developments in Oncology (Hardcover Book) [1989 edition] (1989)

Breast Cancer: Progress in Biolo... (1989)

International Association for Br...

Cover for Harold a Durfee · Phenomenology and Beyond: The Self and Its Language - Contributions to Phenomenology (Hardcover Book) [1989 edition] (1989)

Phenomenology and Beyond: The Se... (1989)

Harold a Durfee

Cover for Reinald Klockenbusch · Husserl und Cohn: Widerspruch, Reflexion, und Telos in Phanomenologie und Dialektik - Phaenomenologica (Hardcover Book) [1989 edition] (1989)

Husserl und Cohn: Widerspruch, R... (1989)

Reinald Klockenbusch

Cover for R. Skousen · Analogical Modeling of Language (Hardcover Book) [1989 edition] (1989)

Analogical Modeling of Language (1989)

Cover for S Matern · Clinical Research in Gastroenterology 2 (Hardcover Book) [2nd 1989 edition] (1989)

2nd 1989 edition

Clinical Research in Gastroenter... (1989)

Cover for Susan Lightman · Immunology of Eye Diseases - Immunology and Medicine (Hardcover Book) [1989 edition] (1989)

Immunology of Eye Diseases - Imm... (1989)

Cover for Kenneth Nowotny · Public Utility Regulation: The Economic and Social Control of Industry - Recent Economic Thought (Hardcover Book) [1989 edition] (1989)

Public Utility Regulation: The E... (1989)

Kenneth Nowotny

Cover for Bo Carlsson · Industrial Dynamics: Technological, Organizational, and Structural Changes in Industries and Firms - Studies in Industrial Organization (Hardcover Book) [1989 edition] (1989)

Industrial Dynamics: Technologic... (1989)

Cover for Pavel B Brazdil · Machine Learning, Meta-Reasoning and Logics - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

Machine Learning, Meta-Reasoning... (1989)

Pavel B Brazdil

Cover for Robert M. Gray · Source Coding Theory - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

Source Coding Theory - The Sprin... (1989)

Cover for Ira Horowitz · Organization and Decision Theory - Recent Economic Thought (Hardcover Book) [1990 edition] (1989)

Organization and Decision Theory... (1989)

Cover for Donald E. Thomas · Algorithmic and Register-Transfer Level Synthesis: The System Architect's Workbench: The System Architect's Workbench - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

Algorithmic and Register-Transfe... (1989)

Donald E. Thomas

Cover for Rainer Feistel · Evolution of Complex Systems: Selforganisation, Entropy and Development - Mathematics and Its Applications (Hardcover Book) (1989)

Evolution of Complex Systems: Se... (1989)

Cover for A. D. Aleksandrov · General Theory of Irregular Curves - Mathematics and Its Applications (Hardcover Book) (1989)

General Theory of Irregular Curv... (1989)

A. D. Aleksandrov

Cover for Sarah Hutton · Henry More (1614-1687) Tercentenary Studies: with a biography and bibliography by Robert Crocker - International Archives of the History of Ideas / Archives Internationales d'Histoire des Idees (Hardcover Book) [1990 edition] (1989)

Henry More (1614-1687) Tercenten... (1989)

Cover for Beltsville Agricultural Research Center · Biotic Diversity and Germplasm Preservation, Global Imperatives - Beltsville Symposia in Agricultural Research (Hardcover Book) [1989 edition] (1989)

Biotic Diversity and Germplasm P... (1989)

Beltsville Agricultural Research...

Cover for Anatol Rapoport · Decision Theory and Decision Behaviour: Normative and Descriptive Approaches - Theory and Decision Library B (Hardcover Book) [1989 edition] (1989)

Decision Theory and Decision Beh... (1989)

Anatol Rapoport

Cover for D. Zolo · Reflexive Epistemology: The Philosophical Legacy of Otto Neurath - Boston Studies in the Philosophy and History of Science (Hardcover Book) [1989 edition] (1989)

Reflexive Epistemology: The Phil... (1989)

Cover for M. I. Rabinovich · Oscillations and Waves: in Linear and Nonlinear Systems - Mathematics and its Applications (Hardcover Book) [1989 edition] (1989)

Oscillations and Waves: in Linea... (1989)

M. I. Rabinovich

Cover for J.H. Baard · Nuclear Data Guide for Reactor Neutron Metrology (Hardcover Book) [1989 edition] (1989)

Nuclear Data Guide for Reactor N... (1989)

Cover for Caribbean Mathematics Foundation Conference 1988 · Ordered Algebraic Structures: Proceedings of the Caribbean Mathematics Foundation Conference on Ordered Algebraic Structures, Curacao, August 1988 - Mathematics and Its Applications (Hardcover Book) [1989 edition] (1989)

Ordered Algebraic Structures: Pr... (1989)

Caribbean Mathematics Foundation...

Cover for David Andrew Kendrick · Models for Analyzing Comparative Advantage - Advanced Studies in Theoretical and Applied Econometrics (Hardcover Book) [1990 edition] (1989)

Models for Analyzing Comparative... (1989)

David Andrew Kendrick

Cover for Jan Stenflo · Solar Photosphere: Structure, Convection, and Magnetic Fields: Proceedings of the 138th Symposium of the International Astronomical Union Held in kiev,USSR, May 15-20, 1989 - International Astronomical Union Symposia (Paperback Book) [Softcover reprint of the original 1st ed. 1990 edition] (1989)

Softcover reprint of the original 1st ed. 1990 edition

Solar Photosphere: Structure, Co... (1989)

Cover for David B Humphrey · The U.S. Payment System: Efficiency, Risk and the Role of the Federal Reserve: Proceedings of a Symposium on the U.S. Payment System sponsored by the Federal Reserve Bank of Richmond (Hardcover Book) [1990 edition] (1989)

The U.S. Payment System: Efficie... (1989)

David B Humphrey

Cover for Kenneth Chilton · American Manufacturing in a Global Market (Hardcover Book) [1989 edition] (1989)

American Manufacturing in a Glob... (1989)

Kenneth Chilton

Cover for Stephen W. Director · VLSI Design for Manufacturing: Yield Enhancement - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

VLSI Design for Manufacturing: Y... (1989)

Stephen W. Director

Cover for S I Akasofu · The Solar Wind and the Earth - Geophysics and Astrophysics Monographs (Closed) (Paperback Book) [Softcover Reprint of the Original 1st Ed. 1987 edition] (1989)

Softcover Reprint of the Original 1st Ed. 1987 edition

The Solar Wind and the Earth - G... (1989)

Cover for I. Novikov · Physics of Black Holes - Fundamental Theories of Physics (Hardcover Book) [1989 edition] (1989)

Physics of Black Holes - Fundame... (1989)

Cover for Gheorghe Constantin · Elements of Probabilistic Analysis with Applications - Mathematics and Its Applications (Hardcover Book) (1989)

Elements of Probabilistic Analys... (1989)

Gheorghe Constantin

Cover for H. Steinmann · World Catalogue of Dermapters (Hardcover Book) [1989 edition] (1989)

World Catalogue of Dermapters (1989)

Cover for Walter Thirring · Lehrbuch Der Mathematischen Physik: Band 2: Klassische Feldtheorie (Paperback Book) [German, 2. Aufl. 1990 edition] (1989)

German, 2. Aufl. 1990 edition

Lehrbuch Der Mathematischen Phys... (1989)

Walter Thirring

Cover for Ulrich Grigull · Steam Tables in Si-units / Wasserdampftafeln: Concise Steam Tables in Si-units (Student S Tables) Properties of Ordinary Water Substance Up to 1000 C (Paperback Book) (1989)

Steam Tables in Si-units / Wasse... (1989)

Cover for F. Selleri · Quantum Paradoxes and Physical Reality - Fundamental Theories of Physics (Hardcover Book) [1990 edition] (1989)

Quantum Paradoxes and Physical R... (1989)

Cover for Paolo Fabbri · Recreational Uses of Coastal Areas: A Research Project of the Commission on the Coastal Environment, International Geographical Union - GeoJournal Library (Hardcover Book) [1990 edition] (1989)

Recreational Uses of Coastal Are... (1989)

Cover for International Conference on Ephemeroptera · Mayflies and Stoneflies: Life Histories and Biology: Proceedings of the 5th International Ephemeroptera Conference and the 9th International Plecoptera Conference - Series Entomologica (Hardcover Book) [1990 edition] (1989)

Mayflies and Stoneflies: Life Hi... (1989)

International Conference on Ephe...

Cover for Charles Hartshorne · Charles Hartshorne's Concept of God: Philosophical and Theological Responses - Studies in Philosophy and Religion (Hardcover Book) [1990 edition] (1989)

Charles Hartshorne's Concept of ... (1989)

Charles Hartshorne

Cover for Stephen J Peroutka · Ecstasy: The Clinical, Pharmacological and Neurotoxicological Effects of the Drug MDMA - Topics in the Neurosciences (Hardcover Book) [1990 edition] (1989)

Ecstasy: The Clinical, Pharmacol... (1989)

Stephen J Peroutka

Cover for Rawal · Spinal Narcotics - Current Management of Pain (Hardcover Book) [1990 edition] (1989)

Spinal Narcotics - Current Manag... (1989)

Cover for W Sieg · Acting and Reflecting: The Interdisciplinary Turn in Philosophy - Synthese Library (Hardcover Book) [1990 edition] (1989)

Acting and Reflecting: The Inter... (1989)

Cover for A.d. Irvine · Physicalism in Mathematics - The Western Ontario Series in Philosophy of Science (Hardcover Book) [1990 edition] (1989)

Physicalism in Mathematics - The... (1989)

Cover for International Conference on Fibonacci Numbers and Their Applications 3rd 1988 · Applications of Fibonacci Numbers: Volume 3 Proceedings of 'The Third International Conference on Fibonacci Numbers and Their Applications', Pisa, Italy, July 25-29, 1988 (Hardcover Book) [1990 edition] (1989)

Applications of Fibonacci Number... (1989)

International Conference on Fibo...

Cover for Nato Advanced Research Workshop on Semiconductor Device Reliability · Semiconductor Device Reliability - Nato Science Series E: (Hardcover Book) [1990 edition] (1989)

Semiconductor Device Reliability... (1989)

Nato Advanced Research Workshop ...

Cover for N.N. Bogolubov · General Principles of Quantum Field Theory - Mathematical Physics and Applied Mathematics (Hardcover Book) [1990 edition] (1989)

General Principles of Quantum Fi... (1989)

Cover for Andreucci · International Yearbook of Nephrology 1990 - International Yearbooks of Nephrology (Hardcover Book) [1990 edition] (1989)

International Yearbook of Nephro... (1989)

Cover for Wojciech Sadurski · Moral Pluralism and Legal Neutrality - Law and Philosophy Library (Hardcover Book) [1990 edition] (1989)

Moral Pluralism and Legal Neutra... (1989)

Wojciech Sadurski

Cover for M.E. Bayles · Procedural Justice: Allocating to Individuals - Law and Philosophy Library (Hardcover Book) [1990 edition] (1989)

Procedural Justice: Allocating t... (1989)

Cover for Nato Advanced Research Workshop on Molecular Mechanisms and Consequences of Activation of Hormone and Growth Factor Receptors · Activation of Hormone and Growth Factor Receptors: Molecular Mechanisms and Consequences - NATO Science Series C (Hardcover Book) [1990 edition] (1989)

Activation of Hormone and Growth... (1989)

Nato Advanced Research Workshop ...

Cover for G. Antonides · The Lifetime of a Durable Good: An Economic Psychological Approach - Theory and Decision Library A: (Hardcover Book) [1990 edition] (1989)

The Lifetime of a Durable Good: ... (1989)

Cover for M D Roth · Doubting: Contemporary Perspectives on Skepticism - Philosophical Studies Series (Hardcover Book) [1990 edition] (1989)

Doubting: Contemporary Perspecti... (1989)

Cover for Patrick Nerhot · Law, Interpretation and Reality: Essays in Epistemology, Hermeneutics and Jurisprudence - Law and Philosophy Library (Hardcover Book) [1990 edition] (1989)

Law, Interpretation and Reality:... (1989)

Cover for Ronald H Ottewill · Scientific Methods for the Study of Polymer Colloids and Their Applications - NATO Science Series C (Hardcover Book) [1990 edition] (1989)

Scientific Methods for the Study... (1989)

Ronald H Ottewill

Cover for Franc\'oise Candau · An Introduction to Polymer Colloids (Paperback Book) [Softcover reprint of the original 1st ed. 1990 edition] (1989)

Softcover reprint of the original 1st ed. 1990 edition

An Introduction to Polymer Colloids (1989)

Franc\'oise Candau

Cover for D T Chapman · Statistical Methods for the Assessment of Point Source Pollution: Proceedings of a Workshop on Statistical Methods for the Assessment of Point Source Pollution, held in Burlington, Ontario, Canada (Hardcover Book) [1989 edition] (1989)

Statistical Methods for the Asse... (1989)

Cover for Mark A. Lutz · Social Economics: Retrospect and Prospect - Recent Economic Thought (Hardcover Book) [1990 edition] (1989)

Social Economics: Retrospect and... (1989)

Cover for Economic Policy Conference of the Federal Reserve Bank of St Louis 13th 1988 · The Stock Market: Bubbles, Volatility, and Chaos (Hardcover Book) [1990 edition] (1989)

The Stock Market: Bubbles, Volat... (1989)

Economic Policy Conference of th...

Cover for William Baumol · The Economics of Mutual Fund Markets: Competition Versus Regulation - Rochester Studies in Managerial Economics and Policy (Hardcover Book) [1990 edition] (1989)

The Economics of Mutual Fund Mar... (1989)

Cover for D Paul Benjamin · Change of Representation and Inductive Bias - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

Change of Representation and Ind... (1989)

D Paul Benjamin

Cover for David Dery · Data and Policy Change: The Fragility of Data in the Policy Context (Hardcover Book) [1990 edition] (1989)

Data and Policy Change: The Frag... (1989)

Cover for Debashis Bhattacharya · Hierarchical Modeling for VLSI Circuit Testing - The Springer International Series in Engineering and Computer Science (Hardcover Book) [1990 edition] (1989)

Hierarchical Modeling for VLSI C... (1989)

Debashis Bhattacharya

Cover for Mary Ellen Waithe · A History of Women Philosophers: Medieval, Renaissance and Enlightenment Women Philosophers A.D. 500-1600 - History of Women Philosophers (Hardcover Book) [1989 edition] (1989)

A History of Women Philosophers:... (1989)

Mary Ellen Waithe

Cover for Mary E Waithe · A History of Women Philosophers: Medieval, Renaissance and Enlightenment Women Philosophers A.D. 500-1600 - History of Women Philosophers (Paperback Book) [Softcover reprint of the original 1st ed. 1989 edition] (1989)

Softcover reprint of the original 1st ed. 1989 edition

A History of Women Philosophers:... (1989)

Cover for Kenneth Zweibel · Harnessing Solar Power: the Photovoltaics Challenge (Paperback Book) [Softcover Reprint of the Original 1st Ed. 1990 edition] (1990)

Softcover Reprint of the Original 1st Ed. 1990 edition

Harnessing Solar Power: the Phot... (1990)

Kenneth Zweibel

Cover for Andrew B. Tullo · Care of the Ophthalmic Patient: a Guide for Nurses and Health Professionals (Paperback Book) (1990)

Care of the Ophthalmic Patient: ... (1990)

Andrew B. Tullo

Cover for Patricia Smith · Practical Physiotherapy with Older People (Therapy in Practice Series) (Paperback Book) (1990)

Practical Physiotherapy with Old... (1990)

Cover for Gelvin, S. B., Purdue University, West Lafayette, IN, USA (Ed. ). · Plant Molecular Biology Manual: Update 1 (Paperback Book) (1990)

Plant Molecular Biology Manual: ... (1990)

Gelvin, S. B., Purdue University...

Cover for Heinz-peter Herbert · Dbase Iv Einsatz in Lokalen Netzwerken (Lan) (Paperback Book) (1990)

Dbase Iv Einsatz in Lokalen Netz... (1990)

Heinz-peter Herbert

Cover for Marie-therese Menager · Nuclear Methods of Dating - Solid Earth Sciences Library (Hardcover Book) [1989 edition] (1990)

Nuclear Methods of Dating - Soli... (1990)

Marie-therese Menager

Cover for Anna-teresa Tymieniecka · Man's Self-Interpretation-in-Existence: Phenomenology and Philosophy of Life Introducing the Spanish Perspective - Analecta Husserliana (Hardcover Book) [1990 edition] (1990)

Man's Self-Interpretation-in-Exi... (1990)

Anna-teresa Tymieniecka

Cover for Trevor H Levere · Nature, Experiment, and the Sciences: Essays on Galileo and the History of Science in Honour of Stillman Drake - Boston Studies in the Philosophy and History of Science (Hardcover Book) [1990 edition] (1990)

Nature, Experiment, and the Scie... (1990)

Trevor H Levere

Cover for Smith, J C, Qc · Historical Foundations of Cognitive Science - Philosophical Studies Series (Hardcover Book) [1990 edition] (1990)

Historical Foundations of Cognit... (1990)

Cover for R.W. Edwards · Acid Waters in Wales - Monographiae Biologicae (Hardcover Book) [1990 edition] (1990)

Acid Waters in Wales - Monograph... (1990)

Cover for M Munawar · Environmental Bioassay Techniques and their Application: Proceedings of the 1st International Conference held in Lancaster, England, 11-14 July 1988 - Developments in Hydrobiology (Hardcover Book) [188th 1989 edition] (1990)

188th 1989 edition

Environmental Bioassay Technique... (1990)

Cover for O Guvenen · Crosslinking and Scission in Polymers - NATO Science Series C (Hardcover Book) [1990 edition] (1990)

Crosslinking and Scission in Pol... (1990)

Cover for Leonardas Kairioukustis · Methods of Dendrochronology: Applications in the Environmental Sciences (Hardcover Book) [1990 edition] (1990)

Methods of Dendrochronology: App... (1990)

Leonardas Kairioukustis

Cover for Kona Symposium on Millimetre and Submillimetre Astronomy · Submillimetre Astronomy: Proceedings of the Kona Symposium on Millimeter and Submillimetre Astronomy, Held at Kona, Hawaii, October 3-6, 1988 - Astrophysics and Space Science Library (Hardcover Book) [1990 edition] (1990)

Submillimetre Astronomy: Proceed... (1990)

Kona Symposium on Millimetre and...

Cover for R.L. Dukes · Worlds Apart: Collective Action in Simulated Agrarian and Industrial Societies - Theory and Decision Library A: (Hardcover Book) [1990 edition] (1990)

Worlds Apart: Collective Action ... (1990)

Cover for Harvey Sacks · Harvey Sacks Lectures 1964-1965 (Hardcover Book) [Reprinted from HUMAN STUDIES, 12:3-4, 1990 edition] (1990)

Reprinted from HUMAN STUDIES, 12:3-4, 1990 edition

Harvey Sacks Lectures 1964-1965 (1990)

Cover for Y. Barroux · Monetary Policy: A Theoretical and Econometric Approach - Advanced Studies in Theoretical and Applied Econometrics (Hardcover Book) [1990 edition] (1990)

Monetary Policy: A Theoretical a... (1990)