APA (7th ed.) Zitazioa

Lewis, D. (1984). Pencil drawing techniques. Watson-Guptill Publications.

Chicago Style (17th ed.) Zitazioa

Lewis, David. Pencil Drawing Techniques. New York: Watson-Guptill Publications, 1984.

MLA (9th ed.) Zitazioa

Lewis, David. Pencil Drawing Techniques. Watson-Guptill Publications, 1984.