Trexler Library has a selection of documentaries available. To search for them, use Encompass Search in the library homepage. Enter keywords that describe your topic area of interest. From your search results page, choose Videos under the format menu on the sidebar.
You might also find general web searching useful to locate documentaries beyond the library's collection. While we're not able to request DVDs/VHS tapes from other libraries using interlibrary loan, you might be able to find clips or even entire documentaries posted online.