Encyclopedias and Reference Books
Encyclopedias and other reference books
contain factual articles on many subjects, and are a good place to get an overview of a topic. Reference books include dictionaries, atlases and sourcebooks on various subjects.
There are two
types of encyclopedias -- general and subject. General encyclopedias
provide overviews on a wide variety of topics. Subject encyclopedias
contain entries focusing on one field of study, such as Biology or Art.