Cita APA (7a ed.)

Hempel, A. G., Meloy, J. R., & Richards, T. C. (1999). Offender and offense characteristics of a nonrandom sample of mass murderers.

Cita Chicago Style (17a ed.)

Hempel, A. G., J. R. Meloy, y T. C. Richards. Offender and Offense Characteristics of a Nonrandom Sample of Mass Murderers. 1999.

Cita MLA (8a ed.)

Hempel, A. G., et al. Offender and Offense Characteristics of a Nonrandom Sample of Mass Murderers. 1999.