Use the Catalogue to find your scholarly books. Most books you will find fall into this category. You can limit the results of your searches to books by selecting "Book" from the format menu on the left side of your list of search results.
One useful way is to find the appropriate subject headings. Subject headings are useful because they bring all the books on a given subject together, regardless of the keywords in the title. There are several kinds of headings: people, places, events, and concepts being the most obvious.
The best way to approach subject headings is to start with some words you know to be appropriate for your topic and search them in the Catalogue. Look at the records for the books you find and locate the subject headings, such as the example below. Which of the headings on these the Catalogue records is the most appropriate for the aspects of your topic that you want to study? You can click on it to find other books on the topic.
References in modern secondary works, either articles or chapters of books dealing with your topic are also a useful source for finding still more relevant works. But remember, while you can build up a very useful chain of references, it will only lead backwards in time. More recent references will only come from the Catalogue.
A recent book by a recognized scholar on any subject will usually be a good starting point for that subject. Review the points about scholarly and popular works mentioned above.
Once you find your book, ask yourself the following questions:
A recent scholarly book is not only a good starting point for your research, but it is also one of the best sources for all your other primary and secondary sources. If you are missing any of the items, you might be able to find them in the bibliography or footnotes.