The most direct way to find films is a keyword search in our library catalog, restricting to the "Videos & DVDs" category.
Most films receive a subject heading indicating genre. There are a few documentary-related headings: “Documentary films”, “Documentary television programs”, and “Documentary-style films”.
So -- to search the catalog for documentary films on a particular topic, try a keyword search for:
documentary and [your search term], limited to the Videos & DVDs category.
Hint: broaden your search term using the wildcard (asterisk *) in order to find spelling variants
Example: documentary and global