Não informado. (1993). Technical Education & Training Abstracts. Carfax Publishing.
Chicago-Zitierstil (17. Ausg.)Não informado. Technical Education & Training Abstracts. Oxfordshire, Inglaterra: Carfax Publishing, 1993.
MLA-Zitierstil (8. Ausg.)Não informado. Technical Education & Training Abstracts. Carfax Publishing, 1993.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.