APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (8th ed.) Citation

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