Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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