Encyclopedias contain brief factual articles on many subjects. There are two types of encyclopedias -- general and subject.
Use wisely and with a bit of skepticism! Verify using other possibly more reliable sources. Professors at WPI generally don't want to see Wikipedia references in bibliographies. Wikipedia can be a useful starting point as you look for ideas of what you want to learn more about, but it is not a source that you will cite in your paper. Remember this rule: Wikipedia is a good place to start but not a good place to finish.
varied, some are scholars.
sometimes short, designed to give an overview of a subject
Many encyclopedias are available online.
Example hardcopy encyclopedia reference citation in American Psychological Association (APA)style:
Yang, G. W. (2009). Thermodynamic and kinetic theories of nanowire growth. In Encyclopedia of nanotechnology (Vol. 1, pp. 201-235). Nova Science Publishers.
Example electronic encyclopedia reference citation in American Psychological Association (APA) style:
Brunell, L. (2020). Feminism. In Encyclopædia Britannica. http://www.britannica.com/EBchecked/topic/724633/feminism
For information on additional citation styles, please see the Citing Sources guide.