The EOLSS body of knowledge is an integrated compendium of TWENTY component encyclopedias (also known as subject categories in the taxonomy of EOLSS). Their titles and main contents are set out below. Within these TWENTY on-line encyclopedias, there are one hundred and eighty five Themes ,each of which has been complied under the editorial supervision of a recognized world expert .Each of these 'Honorary Theme editors' was responsible for recruiting and appropriate selection of authors to produce the material specified by EOLSS. The size of a theme in the EOLSS may vary from about 10 chapters to about 240 chapters. The size of an entry (chapter) in the EOLSS may vary from about 5000 words to about 30 000 words. The EOLSS attempts to forge pathways between  disciplines in order to show their interdependence and help foster the transdisciplinary aspects of the relationship between nature and human society (the anthroposphere). It deals in detail with interdisciplinary subjects ,but it is also disciplinary  as each major core subject is covered in great depth by world experts. at the time of preparation of this EOLSS STUDY GUIDE, EOLSS has reached a size of 55 million words. Most of the themes have been completed but the virtual library will be augmented and updated almost as often as every Month (augmenting refers to addition of new material and updating is the process of revising existing material to bring it up to date ).About twenty Themes are still under development and will be available online in due course. It has been developed under the auspices of UNESCO and published by Eolss publishers, Oxford, UK

This Study Guide (which is updated bimonthly) provides a road map to help the user find  his/her way around EOLSS . It facilities rapid identification and retrieval of the most relevant material. For example university lectures will find it useful in ensuring comprehensive coverage of their chosen  subject and invaluable aid in lecture and seminar preparation. It can be used in research and preparation of study notes , papers ,reports, theses, dissertations ,etc. Every chapter is reviewed to ensure that the contributions meet the required standards of comprehensiveness, clarity, coherance and consistency and that the material is factually correct and helpful in self study

The Scope of the coverage that has been completed to date, under the content outline and subject index for each of the TWENTY encyclopedias. The content outline provides a topical index (about 46,000) within all the encyclopedias, is indicated under the Content Outline (see below).

  Advanced Geographic Information Systems

  Environmental Structure and Function: Climate System

  Environmental Structure and Function: Earth System

  Geography

  Geoinformatics

  Geology

  Geophysics and Geochemistry

  Natural Disasters

  Oceanography

  Computational Methods and Algorithms

  Mathematical Models

  Mathematics: History, Concepts, and Foundations

  Optimization and Operations Research

  Probability and Statistics

  Systems Science and Cybernetics

  Environmetrics

  Biometrics

  Biological Systematics

  Biotechnology

  Extremophiles

  Fundamentals of Biological Science: An Evolutionary Approach

  Fundamentals of Life

  Genetics and Molecular Biology

  Global Perspectives in Health

  Physiology and Maintenance

  Water and Health

  Archaeology

  Culture, Civilization and Human Society

  Education for Sustainability

  Environmental Laws and Their Enforcement

  Fundamental Economics

  Government and Politics

  History

  Journalism and Mass Communication

  Law

  Literature and the Fine Arts

  Management

  Psychology

  Sociology

  Unity of Knowledge (in Transdisciplinary Research for Sustainability)

  Civil Engineering

  Control Systems, Robotics, and Automation

  Electrical Engineering

  Industrial and Manufacturing Engineering

  Materials Science and Engineering

  Mechanical Engineering

  Physical Methods, Instruments and Measurements

  Physics

  Transportation Engineering and Planning

ENCYCLOPEDIA OF CHEMICAL SCIENCES ENGINEERING AND TECHNOLOGY RESOURCES

   Chemical Ecology

  Chemical Engineering

  Chemical Education

  Environmental and Ecological  Chemistry

  Fundamentals of Chemistry

  Main Branches of Chemistry

  Environmental and Health aspects of Water  Treatment and supply

  Fresh Surface water

  Future Challenges of Providing High-Quality Water

  Groundwater

  Hydrological Structures, Equipment and water data Acquisition Systems

  Hydrological Cycle

  Types and Properties of Waters

  Wastewater Recycle, Reuse, and Reclamation

  Water and Development

  Water and Wastewater Treatment

  Water Hazards Caused by Naturally Occurring Hydrologic Extremes

  Water Interactions with Energy, Environment and Food & Agriculture

  Water Quality and Standards

  Water Resources Management

  Water Storage, Transport, and Distribution

  Water-Related Education, Training and Technology Transfer

  Air Conditioning -Energy Consumption and Environmental Quality 

  Chemical Energy Plants

  Coal, Oil Shale, Natural Bitumen, Heavy Oil and Peat

  Efficient Use and Conservation of Energy

  Electrical Energy Systems

  Energy Carriers and Conversion Systems

  Energy Policy

  Energy Storage Systems

  Energy Supply and Demand

  Energy Transportation

  Exergy, Energy System Analysis, and Optimization

  Introduction to Energy and Energy Related Concepts of Sustainability

  Nuclear Energy Materials and Reactors

  Oil and Natural Gas

  Renewable Energy Sources Charged with Energy from the Sun and    Originated from  Earth-Moon Interaction

  Renewable Energy Systems: Direct Solar Energy

  Thermal Power Plants

  Thermal to Mechanical Energy Conversion: Engines and Requirements

  Anthropogenic Causes of Global Environmental Change

  Biodiversity: Structure and Function

  Coastal Zones and Estuaries

  Ecology

  Engineering Geology, Environmental Geology & Mineral Economics

  Environmental Education and Awareness

  Environmental Indicators and Assessment

  Environmental Monitoring

  Environmental Regulations and Standard Setting

  Environmental Systems

  Environmental Toxicology and Human Health

  Hazardous Waste Management

  Interactions: Energy/Environment

  Interactions: Food & Agriculture/Environment

  Large-Scale Pollution: Global Effects and      Processes

  Marine Ecology

  Point Sources of Pollution: Local Effects and It's Control

  Pollution Control Technologies

  Technological Hazards

  Waste Management and Minimisation

  Agricultural Land Improvement: Amelioration and Reclamation

  Agricultural Mechanization & Automation

  Agricultural Sciences

  Biophysical Factors Affecting Food Supply from Land

  Cultivated Plants, Primarily as Food Sources

  Fisheries and Aquaculture

  Food Engineering

  Food Quality and Standards

  Food Storage and Distribution Systems

  Forests and Forest Plants

  Impacts of Agriculture on Human Health and Nutrition

  Management of Agricultural, Forestry and Fisheries Enterprises

  Public Policy in Food and Agriculture

  Terrestrial Animals: Mammals, Birds and Invertebrates

  The Management of Natural Resources in Satisfying the Need for Human Life

  The Role of Food, Agriculture, Forestry and Fisheries in Human Nutrition

  Human Resources Management

  Population and Development: Challenges and Opportunities

  Quality of Human Resources: Disadvantaged People

  Quality of Human Resources: Education

  Quality of Human Resources: Poverty

  Social and Cultural Development of Human Resources

  Sustainable Human Development

  Biodiversity Conservation and Habitat Management

  Climate Change, Human Systems and Policy

  Earth System: History and Natural Variability

  Land Use and Land Cover

  Natural and Human Induced Hazards

  Natural Resources of the World

  Oceans and Aquatic Ecosystems

  Dimensions of Sustainable Development

  Economics Interactions With Other Disciplines

  Economics of Peace and Security

  Environment and Development

  Global Transformations and World Futures

  International Development Law

  International Economics, Finance and Trade

  Introduction to Sustainable Development

  Principles of Sustainable Development

  Socioeconomic Development

  Welfare Economics & Sustainable Development

  Conflict Resolution

  Conventions, Treaties and other Responses to Global Issues

  Democratic Global Governance

  Human Settlement Development

  Institutional Issues Involving Ethics and Justice

  International Law and Institutions

  International Relations

  National, Regional Institutions & Infrastructures

  Public Administration and Public Policy

  Computer Science and Engineering

  Globalization of Technology

  Industrial Ecology and Green Design

  Integrated Global Models of Sustainable Development

  Knowledge Management, Organizational Intelligence and Learning, and Complexity

  Science and Technology Policy

  Sustainable Built Environment

  Systems Analysis and Modeling of Integrated World Systems

  Systems Engineering and Management for Sustainable Development

  Artificial Intelligence

  System Dynamics

  Regional Sustainable Development Review: Africa

  Regional Sustainable Development Review: Brazil

  Regional Sustainable Development Review: Canada and USA

  Regional Sustainable Development Review: China

  Regional Sustainable Development Review: Europe

  Regional Sustainable Development Review: Japan

  Regional Sustainable Development Review: Russia