Lopker, J. (2000). Pictures of personality: Guide to the four human natures (First edition.). Typology.
Citazione stile Chigago Style (17a edizione)Lopker, John. Pictures of Personality: Guide to the Four Human Natures. First edition. Los Angeles, CA: Typology, 2000.
Citatione MLA (8a ed.)Lopker, John. Pictures of Personality: Guide to the Four Human Natures. First edition. Typology, 2000.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.