Finding a known memoir is as simple as searching the author's name or perhaps a few words from the title. But what if you're looking for unknown memoirs by certain kinds of people? Try using the subject field, often found in a database's advanced search options. This will help you home in books by and about certain categories of people. For example, you can pair search terms such as race or ethnicity, geography or region, and format or genre.
Note: when searching library catalogs, use "biography" to find memoirs.