How do I cite an essay included as an appendix to a monograph if the essay’s author differs from that of the monograph?

Note: This post relates to content in the eighth edition of the MLA Handbook. For up-to-date guidance, see the ninth edition of the MLA Handbook.

Cite the essay the same way you would cite an essay in an anthology with one difference: whereas for an anthology you would list the name of the book’s editor in the Contributors element, preceded by the label “edited by,” for a monograph you would list the name of the book’s author in the Contributors element, preceded by the label “by”:

Luhmann, Niklas. “Cognition as Construction.” Luhmann Explained: From Souls to Systems, by Hans-Georg Moeller, Open Court, 2006, pp. 241-60.