Cita APA (7a ed.)

Unamuno, M. d., Kerrigan, A., Nozick, M., Barrett, W. E., & Madariaga, S. d. (1977). The tragic sense of life in men and nations. Princeton University Press.

Cita Chicago Style (17a ed.)

Unamuno, Miguel de, Anthony Kerrigan, Martin Nozick, William E. Barrett, y Salvador de Madariaga. The Tragic Sense of Life in Men and Nations. [Princeton, N.J.]: Princeton University Press, 1977.

Cita MLA (9a ed.)

Unamuno, Miguel de, et al. The Tragic Sense of Life in Men and Nations. Princeton University Press, 1977.