Subject Specific Works

• Interdisciplinary Encyclopedia of Religion and Science (INTERS) is a dynamic, on-line only data base, consisting in extensive, updated entries, signed by scholars who are accomplished in both scientific and humanistic research work
• Stanford Encylopedia of Philosophy
• Encyclopedia of Mathematics from Springer. The Encyclopedia of Mathematics wiki is an open access resource designed specifically for the mathematics community. The original articles are from the online Encyclopaedia of Mathematics, published by Kluwer Academic Publishers in 2002.
• Encyclopedia of Earth Expert-reviewed information about the Earth
• Encyclopedia of Life Global access to knowledge about life on Earth
• DiracDelta Encyclopedia of Science and Engineering
• US National Parks Service Environmental Contaminants Encyclopedia  Focus on environmental toxicology related to fish, wildlife, invertebrates, and other non-human living resources
• Encyclopedia Astronautica a little amateurish in appearance but an informative resource