Gaya APA

Nyval, R, F. (1989). Field crop diseases handbook / Robert F. Nyval (Ed.ke-2). New York: Van Nostrand Reinhold.

Gaya MLA

Nyval, Robert, F.. "Field crop diseases handbook / Robert F. Nyval". Ed.ke-2 New York: Van Nostrand Reinhold, 1989. Textbook.