Reference books include dictionaries, encyclopedia, almanacs, directories, manuals, handbooks, and much more. Reference books can help you:
Encyclopedias provide an overview of knowledge on important subjects. General unabridged dictionaries have good coverage of terms in criminal justices, but are not as complete as dictionaries limited to a particular subject. Guides to the literature introduce a subject field and indicate available resources and the way to use them. Handbooks are similar to encyclopedias but cover a narrower subject area and are usually comprised of a collection of essays written by experts. Manuals provide instructions in how to perform a task.