A good way to expand your research and bibliography is to look at the bibliographies of the items that you have already found. You can also see who has cited specific books and articles; those sources should be on similar topics.
The easiest and quickest way to find who has cited a specific book or article, is to look for it in Google Scholar. Under the title and description, you should see a link that says "cited by". This link will take you to all the other sources of information that have cited it.
Connecting Google Scholar to the McGill Library
To take full advantage of the McGill Library collections and Google Scholar, you can connect them. Go to the settings in Google Scholar, then click on Library Link. Search for and select the McGill University Library. Now when you find an article in Google Scholar, it will take you to the version available at McGill (if the Library has it).