Encyclopedias provide an overview of a topic or a short article. Many instructors will not consider encyclopedias to be suitable for citing in your papers, but encyclopedias can offer orientation to your topic and the better quality ones will provide references for you to use.
A scholarly, multi-disciplinary full-text database with more than 5,300 full-text periodicals, including 4,400 peer-reviewed journals, and indexing and abstracting for more than 9,300 journals.