APA (7e ed.) Bronvermelding

Não informado. (1976). Essence. York University, Atkinson College, Department of Psychology.

Chicago (17e ed.) Bronvermelding

Não informado. Essence. Ontario, Canada: York University, Atkinson College, Department of Psychology, 1976.

MLA (8e ed.) Bronvermelding

Não informado. Essence. York University, Atkinson College, Department of Psychology, 1976.

Let op: Deze citaties zijn niet altijd 100% accuraat.