Gaya APA
LOPKER, J., Easton, T, A. (2000).
Pictures of personality : guide to the four human natures / John Lopker .
Los Angeles:
Typology.
Gaya MLA
LOPKER, John., Easton, Thomas, A..
"Pictures of personality : guide to the four human natures / John Lopker".
Los Angeles:
Typology,
2000.
Text.