"Primary sources are materials produced by people or groups directly involved in the event or topic under consideration, either as participants or witnesses." Secondary sources, on the other hand, "comment on and interpret primary sources".*
*Mary Lynn Rampolla, A Pocket Guide to Writing in History, 4th ed. (Boston: Bedford, 2004), pp. 5-6.
See Primary Sources in American History for details on primary sources and how to find them.
See also materials on the Newspapers & Periodicals tab of this guide.
East Asian History Sourcebook
Great source for Chinese, Japanese and Korean history. Differentiates between primary and secondary sources.
International historical statistics
Worldwide coverage of statistics, including population and vital statistics, labor, agriculture, industry, trade, transport & communications, agriculture, education, and national accounts.
East Asian Studies Research Guides, Princeton University Library
Large collection of links and citations to materials in East Asian Studies.