This guide will help you find secondary sources related to ethical theory. While this guide contains many excellent resources, it's not comprehensive. If you're not finding what you're looking for, don't hesitate to contact Anna or stop by the reference desk.
Never underestimate the power of browsing - if you find a book on the shelf that's useful for your topic, look around at its neighbors. Books are arranged by subject, so chances are you'll find other books nearby that will also be useful!