"Primary sources are materials produced by people or groups directly involved in the event or topic under consideration, either as participants or as witnesses....Some primary sources are written documents, such as letters, diaries, newspaper and magazine articles, speeches, autobiographies, treatises, census data, and marriage , birth, and death registers...(Some primary resources) are not written, like works of art, films, recordings, and interviews."
From Mary Lynn Rampolla, A Pocket Guide to Writing in History (Boston: Bedford/St. Martin's, 2007), 6-7.
The best way to find primary sources in the library catalog is by using Library of Congress Subject Headings, which often include the following words:
However these subject headings are not intuitive, therefore it is best that you do a Keyword search for your topic and one of the words above.
Once you find a title of interest, open the record and link to similar materials by clicking on the appropriate subject heading.