Encyclopedia Britannica
Provider of learning knowledge products through its online resources and distributed books and products.
http://www.britannica.com/
Information Please
Knowledge resources featuring almanacs, atlases, encyclopedia, discitonary, thesaurus, and white pages. v
http://www.infoplease.com/
World Book, Inc.
Official site promoting its excellence in the production of award-winning encyclopedias, reference sources, and multimedia projects for the home and schools.
http://www.worldbook.com/