Reference

books.google.com

Search the full text of books, preview titles and find where to buy or borrow millions of works.

wiktionary.org

A collaborative multilingual dictionary covering word meanings, etymology and pronunciation, free for all.

worldcat.org

A global catalog of library collections, helping you find books, music and more in libraries near you.

thesaurus.com

Find synonyms, antonyms and word definitions to sharpen your writing and expand your vocabulary.

scholar.google.com

A broad search engine for scholarly literature across disciplines and sources, with citation tracking.

openlibrary.org

An open, editable catalog of every book ever published, with free borrowing of digitized titles.

snopes.com

The definitive fact-checking site for urban legends, viral claims and misinformation, with sourced investigations.

wolframalpha.com

A computational knowledge engine that answers factual queries with structured data and step-by-step calculations.

archive.org

Free digital library of books, films, software and the Wayback Machine.

wikipedia.org

The free encyclopedia that anyone can edit.