Non-fiction books in library catalogs like Knox Primo are assigned subject headings. This practice allows books to be grouped together by topic, and also tells you what the books are about.
When you find a relevant book in Knox Primo, look at the subject headings. All the subject headings are links, and if you click on one of them you will see all the other books in Knox Primo that also use that subject heading.
Also look at subject headings to get additional search terms that you might not have thought of!
The Library of Congress Subject Headings list, used by most academic libraries in the United State, is constantly being monitored. New headings are suggested by the library community and by other interested people such as historians. For example, some new headings added recently include new topics:
Deerfield Massacre, Deerfield, Mass., 1704
Hackers in motion pictures
Multilingual television programs
United States--Armed Forces--Immigrants
The Library of Congress also responds to changes in the ways we talk about historical events and to changes in culture, especially related to marginalized and underrepresented people. For example the following heading were recently changed.
Tulsa Race Massacre, Tulsa, Okla., 1921 (changed from Tulsa Race Riot, Tulsa, Okla., 1921)
Bisexual People (changed from Bisexuals in Sept. 2023)
You may encounter subject headings that are out of date as it takes time for the changes to propagate through all the different library catalogs. And, some headings that seems insensitive to us may be under scrutiny at this time. For example, discussion is ongoing about the headings for Indigenous peoples of the Americas.