APA (7e ed.) Bronvermelding

Não informado. (1969). Industrial and Commercial Training. J. Wellens, Industrial and Technical Training.

Chicago (17e ed.) Bronvermelding

Não informado. Industrial and Commercial Training. Guilsborough, Inglaterra: J. Wellens, Industrial and Technical Training, 1969.

MLA (8e ed.) Bronvermelding

Não informado. Industrial and Commercial Training. J. Wellens, Industrial and Technical Training, 1969.

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