0%Knowledge 01%Logic 011%History and Philosophy of Logic 012%Formal Logic, Metalogic, and Applied Logic 02%Mathematics 021%History and Foundations of Mathematics 022%Branches of Mathematics 023%Applications of Mathematics 03%Science 031%History and Philosophy of Science 032%The Physical Sciences 033%The Earth Sciences 034%The Biological Sciences 035%Medicine and Affiliated Disciplines 036%The Social Sciences and Psychology and Linguistics 037%The Technological Sciences 04%History and the Humanities 041%Historiography and the Study of History 042%The Humanities and Humanistic Scholarship 05%Philosophy 051%History of Philosophy 052%The Nature and the Divisions of Philosophy 053%Philosophical Schools and Doctrines 06%Preservation of Knowledge 061%Institutions and Techniques for the Collection, Storage, Dissemination, and Preservation of 062%Storage and Retrieval of Information 063%Institutions for the Advancement and Dissemination of Knowledge 1%Matter and Energy 11%Atoms: Atomic Nuclei and Elementary Particles 111%The Structure and Properties of Atoms 112%The Atomic Nucleus and Elementary Particles 12%Energy, Radiation, and the States and Transformation of Matter 121%Chemical Elements: Periodic Variation in Their Properties 122%Chemical Compounds: Molecular Structure and Chemical Bonding 123%Chemical Reactions 124%Heat, Thermodynamics, and the Nonsolid States of Matter 125%The Solid State of Matter 126%Mechanics of Particles, Rigid Bodies, and Deformable Bodies: Elasticity, Vibrations, and Flow 127%Electricity and Magnetism 128%Waves and Wave Motion 13%The Universe: Galaxies, Stars, the Solar System 131%The Cosmos 132%Galaxies and Stars 133%The Solar System 2%Earth 21%The Earth's Properties, Structure, and Composition 211%The Planet Earth 212%The Earth's Physical Properties 213%The Structure and Composition of the Earth's Interior 214%The Earth's Constituent Minerals and Rocks 22%The Earth's Envelope: Its Atmosphere and Hydrosphere 221%The Atmosphere 222%The Hydrosphere: the Oceans, Freshwater Bodies, and Ice Masses 223%Weather and Climate 23%The Earth's Surface Features 231%Physical Features of the Earth's Surface 232%Features Produced by Geomorphic Processes Acting on the Earth's Surface 24%The Earth's History 241%Origin and Development of the Earth and Its Envelopes 242%The Interpretation of the Geologic Record 243%The Eras and Periods of Geologic Time 3%Life 31%The Nature and Diversity of Living Things 311%Characteristics of Living Things 312%The Origin of Life and the Evolution of Living Things 313%The Classification of Living Things 32%The Molecular Basis of Vital Processes 321%Chemicals and the Vital Processes 322%Metabolism: Bioenergetics and Biosynthesis 323%Vital Processes at the Molecular Level 33%The Structures and Functions of Organisms 331%The Cellular Basis of Form and Function 332%The Relation of Form and Function in Organisms 333%Coordination of Vital Processes: Regulation and Integration 334%Covering and Support: Integumentary, Skeletal, and Musculatory Systems 335%Nutrition: the Procurement and Processing of Nutrients 336%Gas Exchange, Internal Transport, and Elimination 337%Reproduction and Sex 338%Development: Growth, Differentiation, and Morphogenesis 339%Heredity: the Transmission of Traits 34%Behavioral Responses of Organisms 341%Nature and Patterns of Behavioral Responses 342%Development and Range of Behavioral Capacities: Individual and Group Behavior 35%The Biosphere: the World of Living Things 351%Basic Features of the Biosphere 352%Biological Populations and Communities 353%Hazards of Life in the Biosphere: Disease and Death 354%Biogeographic Distribution of Organisms: Ecosystems 355%The Place of Humans in the Biosphere 4%Humankind 41%Stages in the Development of Human Life on Earth 411%Human Evolution 412%Human Heredity: the Races of Mankind 42%The Human Organism: Health and Disease 421%The Structures and Functions of the Human Body 422%Human Health 423%Human Diseases 424%The Practice of Medicine and the Care of Health 43%Human Behavior and Experience 431%Human Nature and Experience: General Considerations 432%Influence of the Current Environment on a Person's Behavior and Conscious Experience: Attention, Sensation, and Perception 433%Current Internal States Affecting a Person's Behavior and Conscious Experience 434%Persisting Capacities and Inclinations That Influence Human Behavior and Conscious Experience 435%Development of a Person's Potentials: Learning and Thinking 436%Personality and the Self: Integration and Disintegration of the Person as a Whole 5%Society and Culture 51%Social Groups: Peoples and Cultures 511%Peoples and Cultures of the World 512%The Development of Human Culture 513%Major Cultural Components and Institutions of Human Societies 514%Language and Communication 515%Nations and Political Regions 516%Cities 52%Social Organization and Social Change 521%Social Structure and Change 522%The Group Structure of Society 523%Social Status 524%Human Populations: Urban and Rural Communities 53%The Production, Distribution, and Utilization of Wealth 531%Economic Concepts, Issues, and Systems 532%The Consumer and the Market: Pricing and the Mechanisms for Distributing Goods 533%The Organization of Production and Distribution 534%The Distribution of Income and Wealth 535%Macroeconomics 536%Economic Growth and Planning 54%Politics and Government 541%Political Theory 542%Political Institutions: the Structure, Branches, and Offices of Government 543%The Functioning of Government: the Dynamics of the Political Process 544%International Relations: Peace and War 55%Law 551%Philosophies and Systems of Law; the Practice of Law 552%Branches of Public Law, Substantive and Procedural 553%Branches of Private Law, Substantive and Procedural 56%Education 561%The Aims and Organization of Education 562%Education Around the World 57%Subsistence and Leisure 571%The Means of Subsistence 572%Leisure and play 6%Art 61%Art in General 611%Theory and Classification of the Arts 612%Experience and Criticism of Works of Art; the Nonaesthetic Context of Art 613%Characteristics of the Arts in Particular Cultures 62%The Particular Arts 621%Literature 622%Theatre 623%Motion Pictures 624%Music 625%Dance 626%Architecture, Garden and Landscape Design, and Urban Design 627%Sculpture 628%Drawing, Painting, Printmaking, and Photography 629%Arts of Decoration and Functional Design 7%Technology 71%The Nature and Development of Technology 711%Technology: Its Scope and History 712%The Organization of Human Work 72%Elements of Technology 721%Technology of Energy Conversion and Utilization 722%Technology of Tools and Machines 723%Technology of Measurement, Observation, and Control 724%Extraction and Conversion of Industrial Raw Materials 725%Technology of Industrial Production Processes 73%Major Fields of Technology 731%Agriculture and Food Production 732%Technology of the Major Industries 733%Construction Technology 734%Transportation Technology 735%Technology of Information Processing and of Communications Systems 736%Military Technology 737%Technology of the Urban Community 738%Technology of Earth and Space Exploration 8%Religion 81%Religion in General 811%Knowledge and Understanding of Religion 812%The Religious Life: Institutions and Practices 82%The Particular Religions 821%Prehistoric Religion and Primitive Religion 822%Religions of Ancient Peoples 823%Hinduism and Other Religions of India 824%Buddhism 825%Indigenous Religions of East Asia: Religions of China, Korea, and Japan 826%Judaism 827%Christianity 828%Islam 829%Other Religions and Religious Movements in the Modern World 9%History 91%Ancient Southwest Asia, North Africa, and Europe 911%Early Peoples and Civilizations of Southwest Asia and Egypt, the Aegean, and North Africa 912%Peoples of Ancient Europe and the Classical Civilizations of the Ancient Mediterranean World to AD 395 92%Medieval Europe, North Africa, and Southwest Asia 921%Western Europe, the Byzantine (Eastern Roman) Empire, and Eastern Europe from AD 395 to c 1050 922%The Formative Period in Islamic History, from AD 622 to c 1055 923%Western Christendom in the High and Later Middle Ages (c 1050-c 1500) 924%The Crusading Movement, the Islamic States of Southwest Asia, North Africa, and Europe, and the States of Eastern Christendom from c 1050 to c 1480 93%Peoples and Traditional Civilizations of East, Central, South, and Southeast Asia 931%China to the Beginning of the Late T'ang (AD 755) 932%China from the Late T'ang (AD 755) to the Late Ch'ing (c 1839) 933%Inner (Central and Northeast) Asia to c 1750 934%Japan to the Meiji Restoration (1868), and Korea to 1910 935%The Indian Subcontinent and Ceylon to c AD 1200 936%The Indian Subcontinent from c 1200 to 1761, and Ceylon from c 1200 to 1505 937%The Peoples and Civilizations of Southeast Asia to c 1600 94%Sub-Saharan Africa to 1885 941%West Africa to c 1885 942%The Nilotic Sudan and Ethiopia from c AD 550 to 1885 943%East Africa and Madagascar to c 1885 944%Central Africa to c 1885 945%Southern Africa to c 1885 95%Pre-Columbian America 951%Andean Civilization to c AD 1540 952%Meso-American Civilization to c AD 1540 96%The Modern World to 1920 961%Western Europe from c 1500 to c 1789 962%Eastern Europe, Southwest Asia, and North Africa from c 1480 to c 1800 963%Europe from 1789 to c 1920 964%European Colonies in the Americas from 1492 to c 1790 965%Development of the United States and Canada from 1763 to 1920 966%Development of the Latin-American and Caribbean Nations to c 1920 967%Australia and Oceania to c 1920 968%South Asia Under the Influence of European Imperialism from c 1500 to c 1920 969%Southeast Asia Under the Influence of European Imperialism to c 1920 9610%China from 1839 Until the Onset of Revolution (to c 1911), and Japan from the Meiji Restoration to c 1910 9611%Southwest Asia and North Africa (c 1800-1920), and Sub-Saharan Africa (1885-c 1920) Under the Influence of European Imperialism: the Early Colonial Period 97%The World Since 1920 971%International Movements, Diplomacy, and War Since 1920 972%Europe Since c 1920 973%The United States and Canada Since 1920 974%Latin-American and Caribbean Nations Since c 1920 975%East Asia: China in Revolution, the Era of Japanese Hegemony, and the Influence of the United States in the 20th Century 976%South and Southeast Asia: the Late Colonial Period and the Emergence of New Nations Since 1920 Australia and Oceania Since 1920 977%Australia and Oceania Since 1920 978%Southwest Asia and Africa: the Late Colonial Period and the Emergence of New Nations in the 20th Century