Peckworth, H. F. (1961). Concrete pipe for irrigation and drainage. Chicago: American Concrete Pipe Association.
Παραπομπή Chicago StylePeckworth, Howard F. Concrete Pipe for Irrigation and Drainage. Chicago: American Concrete Pipe Association, 1961.
Παραπομπή MLAPeckworth, Howard F. Concrete Pipe for Irrigation and Drainage. Chicago: American Concrete Pipe Association, 1961.
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