Não informado. (1969). Industrial and Commercial Training. J. Wellens, Industrial and Technical Training.
Čikaški stil citiranja (17. izdanje)Não informado. Industrial and Commercial Training. Guilsborough, Inglaterra: J. Wellens, Industrial and Technical Training, 1969.
MLA način citiranja (8. izdanje)Não informado. Industrial and Commercial Training. J. Wellens, Industrial and Technical Training, 1969.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.