APA (7th ed.) Citation

Compañía Minera de Peñoles & Savage, J. P. (1931). Tunnel driving methods used at Ojuela unit of Compania Minera de Penoles, S. A., Ojuela, Durango, Mexico. [publisher not identified].

Chicago Style (17th ed.) Citation

Compañía Minera de Peñoles and John P. Savage. Tunnel Driving Methods Used at Ojuela Unit of Compania Minera De Penoles, S. A., Ojuela, Durango, Mexico. Washington, D.C.: [publisher not identified], 1931.

MLA (9th ed.) Citation

Compañía Minera de Peñoles and John P. Savage. Tunnel Driving Methods Used at Ojuela Unit of Compania Minera De Penoles, S. A., Ojuela, Durango, Mexico. [publisher not identified], 1931.