SuperSearch can also be used to find primary sources.
Put your search terms in and, on the results page, use the filters to select content types like video, magazine articles, and government documents:
If your research is about a specific time period, scroll down to filter by time, too:
Journals printed c.1685–1835, illuminating 18th-century social, political and literary life. Topics covered include colonial life, provincial and rural affairs, the French and American revolutions, reviews of literature and fashion throughout Europe, political debates, and London coffee house gossip and discussion.