|1||Google and Open Directory reference
General reference resources such as calendars, dictionaries, directories, thesauri, atlases and other geographical materials, and biographies of famous people are becoming quite easy to access online, free of charge. You can find them easily by going into the reference sections of the Google Directory or the Open Directory.
|2||Columbia and Wikipedia encylopedia
Encylopedia that is available free online
|3||Invasive Species Compendium
The Invasive Species Compendium is an online, open access reference work covering recognition, biology, distribution, impact and management of the world's invasive plants and animals
The Invasive Species Compendium currently covers over 1,500 species with over 7,000 basic summary datasheets and 1,500 detailed datasheets. You can also access over 800 full text articles (in pdf format) and 65,000 abstract summaries, with plans to add 10,000 more by the end of 2011. This new resource has been built upon a brand new technical platform which enables our experts to update the datasheets and bibliographical data on a weekly basis
an online encylopedia written by volunteer contributors, rather than by topic experts selected by an editor. The plus side of Wikipedia is that it is huge and has articles covering just about everything. The negative side is that you cannot see who has written the article and what credentials that person has. It Is a fine place to start in finding information, but use it with caution, and dont include references to Wikipedia articles in academic papers. If you find an interesting Wikipedia article that seems to be solid, it will have a list of references at the bottom, which will lead you to the original sources, including books, journal articles, and grey literature.
|5||Medical dictionary at NLM||63|
|6||Medical encylopedia at NLM||56|
|7||Encyclopedia of Life Sciences
includes over 12 million words, 4,000 articles, 7,500 illustrations, 180,000 index entries and 26,000 links. It is constantly updated online
|8||Facts and Comparisons
Facts and Comparisons includes A to Z Drug Facts, Drug Facts and Comparisons, Drug Interaction Facts, drug identification tool, herbal interaction facts, MedFacts Patient Information, Nonprescription Drug Therapy, Review of Natural Products, black box warnings, pregnancy and lactation warnings, investigational drugs, manufacturer index, orphan drugs, and normal lab values.
The Oxford English Dictionary Online is the ultimate authority on the evolution of the English language over the last millennium. It traces the usage of words through over 3 million quotations from a wide range of international English language sources, from classic literature and specialist periodicals to film scripts and cookery books.The OED Online also offers access to the Historical Thesaurus of the OED which enables users to explore themes, meanings and ideas through the history of English