The Merriam-Webster Online Dictionary is based on the print version of Merriam-Webster's Collegiate® Dictionary, Eleventh Edition. The online dictionary includes the main A-Z listing of the Collegiate Dictionary, as well as the Abbreviations, Foreign Words and Phrases, Biographical Names, and Geographical Names sections of that book. It also includes 1,000 illustrations and 25 tables.
The Oxford Reference Online Premium contains about 100 dictionary, language reference, and subject reference works published by Oxford University press. It also contains a range of key titles from the acclaimed oxford Companion Series, plus the Oxford Dictionary of Quotations.
The World Book Online Reference Center (now called World Book Student), includes the articles of the World Book Encyclopedia, a Biography Center, dictionary, atlas, an extensive multimedia collection, thousands of editor-selected Web sites, correlations to curriculum standards, and much more.