Não informado. (1993). Technical Education & Training Abstracts. Carfax Publishing.
Chicago-referens (17:e uppl.)Não informado. Technical Education & Training Abstracts. Oxfordshire, Inglaterra: Carfax Publishing, 1993.
MLA-referens (8:e uppl.)Não informado. Technical Education & Training Abstracts. Carfax Publishing, 1993.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.