Standard reference works may be footnoted but no bibliography entry is needed. The article title is preceded by s.v.=sub verbo, which means "Under the title".
9 Encyclopaedia Britannica, 15th ed., s.v. "Purgatory."
10 Columbia Encyclopedia, 6 th ed., s.v. "Napoleon III," http://www.bartleby.com/65/na/Napoleon3.html (accessed January 5, 2003).
For more examples, refer to pp. 715-716 of The Chicago Manual of Style, 15th Ed., 2003.
The referencing recommendations in this guide are based on the Chicago manual of style. 15th ed. Chicago: University of Chicago Press, 2003. Please refer to Chapters 16 and 17 of that manual for further examples.