Reference books include dictionaries, encyclopedias, handbooks, etc.
Reference books may be used early in your research for topic overviews as well as later in your research when you are looking for specific facts and background material.
Largest Ebook Reference Databases - ALL TOPICS
EBook Reference Databases contain Encyclopedias, Dictionaries, Handbooks, Guidebooks, etc. They are good for quick answers and topic overviews.