APA (7 वां संस्करण) प्रशस्ति पत्र

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

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

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

एमएलए (8वां संस्करण) प्रशस्ति पत्र

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