Pamphlets are useful primary sources in that they are often responses to a particular event or situation.

Collections and series of pamphlets often have the word Pamphlets in the title. Narrow with additional keywords, e.g., “Middle East

Individual pamphlets often, by no means always, have the term Pamphlets in the Form/genre or Subject fields in Hollis and WorldCat - both searched together in the Advanced Search Subject search.

Sometimes series-level groups in archival collections are composed of pamphlets.  In Hollis for Archival Discovery searching Pamphlets isolates these series. This search can be focused with topic keywords or by repository.

Find bibliographies of pamphlets in HOLLIS Library Catalog Advanced Search: Subject contains: pamphlets bibliography

A catalogue of pamphlets on economic subjects published between 1750 and 1900 and now housed in Irish libraries, by R. D. Collison Black. Belfast, Queen's University Belfast, 1969, 632 p.

The Loeb Design Library (scroll down) has a huge collection of pamphlets and similar material on cities, landscape architecture and related topics. Search within them in HOLLIS Library Catalog Advanced Search using: Code: Library + Collection.

A few examples of pamphlet collections: