Bibliography Styles Handbook     

MLA Format: Encyclopedia articles in a bibliography entry

To cite an article in an encyclopedia, use the same format as if it were an item in an anthology (see above), the only difference being that the editor should not be cited. If the passage designates a particular author (sometimes this is done with abbreviations of the author's name - find the entire name of that author elsewhere in the work), give the name of the author first. If there is no explicit author, then give the title first. If the encyclopedia arranges its articles alphabetically, volume and page numbers may be omitted. If the encyclopedia is very familiar and frequently appears in new additions, only the edition and the year of publication.

"Mealworm." Encyclopedia Britannica. 1987 ed.

Garvey, Lawrence. "El Paso, Illinois." Encyclopedia Americana. 1982 ed.