Παραπομπή σε μορφή APA (7η εκδ.)

Walker, T. D. (1977). Plan graphics: Drawing, delineation, lettering (2nd edition.). PDA Publishers.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Walker, Theodore D. Plan Graphics: Drawing, Delineation, Lettering. 2nd edition. West Lafayette: PDA Publishers, 1977.

Παραπομπή σε μορφή MLA (8th εκδ.)

Walker, Theodore D. Plan Graphics: Drawing, Delineation, Lettering. 2nd edition. PDA Publishers, 1977.