Cita APA

Pumphrey, D. L., & Pumphrey, D. L. (1991). Energy policy in the western hemisphere. Washington: Latin American Program Staff.

Citación estilo Chicago

Pumphrey, David L., y David L. Pumphrey. Energy Policy in the Western Hemisphere. Washington: Latin American Program Staff, 1991.

Cita MLA

Pumphrey, David L., y David L. Pumphrey. Energy Policy in the Western Hemisphere. Washington: Latin American Program Staff, 1991.