Cita APA (7a ed.)

Haill, R., Ambler, E., & Anderson, S. (1987). The dark frontier (3rd ed.). Collins ELT.

Cita Chicago Style (17a ed.)

Haill, Richard, Eric Ambler, y Scoular Anderson. The Dark Frontier. 3rd ed. London: Collins ELT, 1987.

Cita MLA (9a ed.)

Haill, Richard, et al. The Dark Frontier. 3rd ed. Collins ELT, 1987.