Note: The only "official" test preparation materials are those produced by the testing company.
These resources represent a small sample of the many books and online test preparation resources available through the HSU Library. To find other test preparation materials at the HSU Library, a good strategy is to search for the name of the test you are interested in along with a term like "examinations" or "study guides" in the library catalog. For example, a keyword search for "GRE and study guides" will find many useful materials.
Once you've found one good book for your needs, try clicking on the subject headings to find more resources on a particular topic.