Look for seed documents:
Find the most recently scholarly works on your topic, look closely at the bibliography for relevant texts.
Skim major reference works: Note titles and authors in recommended reading lists and bibliographies found in major reference books:
Triangulate between search tools for key scholars: Search for your topic in a variety of different locations, e.g. LibrarySearch, Google Scholar, America History & Life etc., making note of the authors whose names appear in each tool.
Use Google Scholar to Cross-reference Titles: Take the list of titles you have accumulated and look for them in Google Scholar to see who has cited them; make particular note of the ones with high citation counts.
Try limiting searches by:
Using a history-specific database can save time by returning more relevant resources faster than in LibrarySearch. Thorough research in a history paper should include one the databases listed below. Note that if your topic crosses geographical regions, you can do a combined search in BOTH databases by selecting the "choose databases" option from within either database.
Use one of history-specific journal article databases on the ARTICLES tab of this guide. Recommended databases:
How to use Historical Abstracts - University of Guelph video 2:07 min. You can apply all the advice given to both Historical Abstracts (world history) and America History & Life (Canadian and US history), since they function identically but search different content.
Using effective search terms is an important part of finding relevant sources.