Reference sources are a great place to start if you want to refresh your memory or learn more about a theory, subject, or topic.
You can find reference sources by searching keywords such as "oxford" or "cambridge" using the Indexes & Databases tab on the library search box, to find resources like some of the ones listed below.
You can also try keyword searches by subject or topic using Summon (use the General tab on the library search box) and limiting your results using the Content Type filter on the left hand side of the page and selecting Reference.
To find more reference books, try browsing these subject headings using the Advanced Search option: