APA (7th ed.) Citation

Welzer, H. (2008). On killing and morality: How normal people become mass murderers. Ordinary people as mass murderers.

Chicago Style (17th ed.) Citation

Welzer, Harald. "On Killing and Morality: How Normal People Become Mass Murderers." Ordinary People as Mass Murderers 2008.

MLA (8th ed.) Citation

Welzer, Harald. "On Killing and Morality: How Normal People Become Mass Murderers." Ordinary People as Mass Murderers, 2008.