APA

Hagen V. W. v., . (1949). Ecuador and the Galápagos Islands. Norman, Oklahoma: University of Oklahoma Press.

Chicago

Hagen Victor Wolfgang von, . 1949. Ecuador and the Galápagos Islands. Norman, Oklahoma: University of Oklahoma Press.

Harvard

Hagen V. W. v., . (1949). Ecuador and the Galápagos Islands. Norman, Oklahoma: University of Oklahoma Press.

MLA

Hagen Victor Wolfgang von, . Ecuador and the Galápagos Islands. Norman, Oklahoma: University of Oklahoma Press. 1949.