Turabian recommends citing encyclopedia articles only in notes and not in a bibliography, but we recommend following the "parts of a book" style, if you do wish to include them in your bibliography.

The citation should include:

• author (if given)
• entry term
• source
• edition and volume
• place of publication
• publisher
• date of publication

Example:

Janos, Adam G. "Cold War." in Encyclopedia Americana. 6th ed.,
Vol.3, New York: Macmillan, 1996.

An alternative form would simply include:

• encyclopedia title
• edition or volume
• s.v. (sub verbo, which means "under the word...")

Example:

Encyclopedia Americana, 6th ed., s.v. "Cold War."