To follow MLA guidelines, the additional information needed for each book entry is a word describing the medium. In MLA format, you typically include the medium of publication at the end of each entry. For printed books, you would include "Print" at the end of each entry.
Here’s how the entries would look with the medium included:
Works Cited
Gregor, Saul. Harnessing the Wind. Chicago: Skyline Publishing, 1998. Print.
Cayman, Felicia. The Windmill Way. Topeka: Heart of America Press, 2010. Print.
Tudor, Tanya. Off-Shore Sources. Portsmouth: Sunshine House, 2008. Print.
Diaz, Carlos. Alternate Energy. New York: Academic Press, 2003. Print.
The other options listed (description of the book’s circulation, the month and day the book was read, and the number of pages in the book) are not typically required in MLA citations.