Different citation styles have specific elements that must be included in an encyclopedia citation. Typically, encyclopedia citations include some or all of the following elements.
Citing Encyclopedias
MLA
Nisbet, Robert A. "Social Science." Encyclopedia Britannica, 2009.
APA
Nisbet, R.A. (2009). Social Science.In Encyclopedia Britannica. Lippincott.
Chicago
Nisbet, Robert A. "Social Science." In Encyclopedia Britannica. Lippincott, 2009.