MLA citation style
Works cited - Article in a reference book or an entry in an encyclopedia
If the article/entry is signed, include the author's name; if unsigned, begin with the title of the entry.
Example of a signed article:
Guignon, Charles B. "Existentialism." Routledge Encyclopedia of Philosophy, edited by Edward Craig, Routledge, 1998.
Example of an unsigned article:
“Niagara Falls.” Encyclopaedia Britannica. Encyclopaedia Britannica, Inc., 2016.