Cita APA (7a ed.)

Lopker, J. (2000). Pictures of personality: Guide to the four human natures (First edition.). Typology.

Cita Chicago Style (17a ed.)

Lopker, John. Pictures of Personality: Guide to the Four Human Natures. First edition. Los Angeles, CA: Typology, 2000.

Cita MLA (8a ed.)

Lopker, John. Pictures of Personality: Guide to the Four Human Natures. First edition. Typology, 2000.