APA (7e ed.) Bronvermelding

Não informado. (1951). ETS Developments. Educational Testing Service.

Chicago (17e ed.) Bronvermelding

Não informado. ETS Developments. Princeton, NJ: Educational Testing Service, 1951.

MLA (8e ed.) Bronvermelding

Não informado. ETS Developments. Educational Testing Service, 1951.

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