Additional published primary sources, collections of primary sources, and guides to primary sources may be retrieved systematically by subject keyword searches on Roger and Melvyl/WorldCat. One generally effective initial search syntax is: [california] [history] [sources] , as in this sample retrieval. For additional finds you may substitute  with the chronological subject designations [18th century] or [19th century].
To find specific types of published primary sources in subsequent search approaches, replace sources with one of these subject terms: diaries, correspondence, narratives, catalogs, manuscripts, archives, archival.
For the Gold Rush era also try [california] [gold discoveries] [sources] and its variants.