Cita APA (7a ed.)

Fromm, E., & Xirau, R. (1969). The nature of man. MacMillan.

Cita Chicago Style (17a ed.)

Fromm, Erich, y Ramon Xirau. The Nature of Man. London: MacMillan, 1969.

Cita MLA (9a ed.)

Fromm, Erich, y Ramon Xirau. The Nature of Man. MacMillan, 1969.