APA (7th ed.) Zitazioa

Norling, E. R. (1999). Perspective made easy. Dover Publications.

Chicago Style (17th ed.) Zitazioa

Norling, Ernest R. Perspective Made Easy. Mineola, N.Y.: Dover Publications, 1999.

MLA (9th ed.) Zitazioa

Norling, Ernest R. Perspective Made Easy. Dover Publications, 1999.