Não informado. (1926). General contracting. Engineering and Contracting Publishing.
Chicago-Zitierstil (17. Ausg.)Não informado. General Contracting. Chicago, Ill: Engineering and Contracting Publishing, 1926.
MLA-Zitierstil (8. Ausg.)Não informado. General Contracting. Engineering and Contracting Publishing, 1926.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.