MLA recommends working the citation information into the text of the relevant paragraph/section/sentence.
List by title of the book. Incorporate these entries alphabetically just as you would with works that include an author name. For example, the following entry might appear between entries of works written by Dean, Shaun and Forsythe, Jonathan.
Encyclopedia of Indiana. Somerset, 1993.
Remember that for an in-text (parenthetical) citation of a book with no author, provide the name of the work in the signal phrase and the page number in parentheses. You may also use a shortened version of the title of the book accompanied by the page number. For more information see the In-text Citations for Print Sources with No Known Author section of In-text Citations: The Basics.