Suggested very broad keyword searches:
[YOUR TOPIC OR NAME] AND (diaries OR diary OR correspondence OR letters OR interviews OR "personal narratives" OR "personal narrative" OR "oral histories" OR "oral history" OR autobiograph* OR memoir* OR sermon* OR speeches OR speech OR addresses OR address)
[YOUR TOPIC OR NAME] AND ("documentary histories" OR "documentary history" OR archives OR sources)
For a more specific search, search Compass or WorldCat:
Cocteau AND diaries
soldiers AND diaries
"Canadian Americans" AND diaries
to broaden the search: "Canadian Americans" AND (diaries OR diary)
"Scholl, Hans" AND correspondence
"college students" AND correspondence
naturalists AND correspondence
Mitchell AND interviews
businesswomen AND interviews
"Hurricane Katrina" AND "personal narratives"
"Korean War" AND "personal narratives"
"Twain, Mark"
china AND travel
To narrow your search even more, you can search the following terms/phrases in subject headings:
addresses, correspondence, diaries, interviews, letters, personal narratives, sermons, speeches, archives, sources.
The World War I Document Archive, Brigham Young University Library
Search Google for online libraries or archives on World War I using a search like:
"world war i" AND (library or archive) AND site:.xx
where xx is a top-level domain for a country of interest. Some example results:
See the list of Country code top-level domains.