World Book
World Book Online Info Finder. Reference content plus science fair projects, a Biography Center, links to world newspapers, 21st century research guides, and much more.
http://worldbookonline.com/

Reference: Thesaurus, Usage, Quotations, and more. Bartleby.com
Bartleby.com offers a wide range of classic full-text searchable reference works.
http://www.bartleby.com/reference/

Bartleby.com: Great Books Online -- Quotes, Poems, Novels ...
Bartleby.com publishes thousands of free online classics of reference, literature and nonfiction
http://www.bartleby.com/

Protocol Online - Your lab's reference book
Database of research protocols in bioscience including molecular biology, cell biology, immunology, plant biology, developmental biology, neuroscience, bioinformatics ...
http://www.protocol-online.org/

Free News, Magazines, Newspapers, Journals, Reference Articles and ...
Free Online Library: One of the largest online libraries in the world -- Millions of news, trade publications, newspapers, magazine, journal and reference documents ...
http://www.thefreelibrary.com/

The Online Books Page - Digital.library server at Penn Libraries
Listing over 1 million free books on the Web - Updated Friday, April 27, 2012
http://digital.library.upenn.edu/books/

Infoplease: Encyclopedia, Almanac, Atlas, Biographies, Dictionary ...
Infoplease.com, a free, authoritative, and respected reference for Internet users, provides a comprehensive encyclopedia, almanac, atlas, dictionary, and thesaurus.
http://www.infoplease.com/

Dictionary.com | Find the Meanings and Definitions of Words at ...
Dictionary.com - the largest and most trusted free online dictionary. Quickly find accurate definitions and audio pronunciations of words.
http://dictionary.reference.com/

Reference Book
In comparison, a reference book or reference-only book in a library is one that may only be used in the library and not borrowed from the library, How To reference a ...
http://openreferencebook.com/

Life Science Reference - Biology Online
Biology Online, information in the life sciences in the form of tutorials, references and an online dictionary of biology terms.
http://www.biology-online.org/