Não informado. (1926). General contracting. Engineering and Contracting Publishing.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. General Contracting. Chicago, Ill: Engineering and Contracting Publishing, 1926.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. General Contracting. Engineering and Contracting Publishing, 1926.
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