Cita APA (7a ed.)

Riley-Smith, J. S. C. (1985). What were the crusades? MacMillan.

Cita Chicago Style (17a ed.)

Riley-Smith, Jonathan Simon Christopher. What Were the Crusades? London: MacMillan, 1985.

Cita MLA (9a ed.)

Riley-Smith, Jonathan Simon Christopher. What Were the Crusades? MacMillan, 1985.