There are two primary ways to identify books. One is searching through catalogs, like the KU Libraries Catalog and WorldCat. The other is to utilize bibliographies from books and articles. Once you have a title of a work, use these catalogs to see KU owns it. If not order it through Interlibrary Loan.
Examples of keywords that retrieve primary sources: sources, personal narratives, diaries, papers, letters, documents. Another way to find primary sources is to do an author search of the individual or organization whose writings you hope to find.
Here is an example of how to use the Advanced Search