Cita APA (7a ed.)

American Geographical Society of New York. (1952). Rio Purús. Army Map Service.

Cita Chicago Style (17a ed.)

American Geographical Society of New York. Rio Purús. s.l.: Army Map Service, 1952.

Cita MLA (8a ed.)

American Geographical Society of New York. Rio Purús. Army Map Service, 1952.