It is important to be able to recognize primary sources when you see them. Items that were created during the time period being studied usually qualify as primary sources. Secondary sources are useful sources of information ABOUT the time period that were created well after the event and usually use primary sources to help tell the story of the event.
"Primary vs. Secondary Sources." General History Guide, FIU Libraries,
library.fiu.edu/history/primary. Chart.
When searching in the library catalog be on the look out for collections that contain the following terms that suggest that book contains primary sources: DOCUMENTS, SOURCES, PERSONAL NARRATIVES, DIARIES, SPEECHES, PAPERS
Don't forget that you can click on the subject heading for SOURCES under the explore section of the book's record.