If, after you've assembled your list of sources, you feel your coverage of the subject is a little "lightweight," and that you may be missing some important sources, take a look at the footnotes/endnotes and bibliographies/reference lists attached to the books and articles you have available. Do more than one of them refer to the same source articles or books? Would that article or book be considered important to the subject area?
Take a look at existing bibliographies, which might be a separate book, a journal article, or posted on the Web (but only if it is from a credible, identified source). If several cite the same item and it's relevant to your topic, see if that work is available and if it meets your criteria.
If your sources seem a little scattered and unrelated to each other, consider narrowing down your topic to something more specific, like "Freudian interpretations of Macbeth, 1995-2005" or "Euthanasia in the Netherlands".
Consult with a librarian at the InfoHelp desk or contact your liaison librarian to get more ideas.
We acknowledge the Australian Aboriginal and Torres Strait Islander peoples as the first inhabitants of the nation and acknowledge Traditional Owners of the lands where our staff and students, live, learn and work.