APA (7th ed.) Citation

Sereny, G. (1974). Into that darkness : from mercy killing to mass murder / (by) Gitta Sereny: From mercy killing to mass murder. Deutsch.

Chicago Style (17th ed.) Citation

Sereny, Gitta. Into That Darkness : From Mercy Killing to Mass Murder / (by) Gitta Sereny: From Mercy Killing to Mass Murder. London: Deutsch, 1974.

MLA (9th ed.) Citation

Sereny, Gitta. Into That Darkness : From Mercy Killing to Mass Murder / (by) Gitta Sereny: From Mercy Killing to Mass Murder. Deutsch, 1974.

Warning: These citations may not always be 100% accurate.