APA (7th ed.) Citation

Leonhard, H. (1994). Was verursacht Aids? Psychologie heute, 21(5), 40-50.

Chicago Style (17th ed.) Citation

Leonhard, Hans-Walter. "Was Verursacht Aids?" Psychologie Heute 21, no. 5 (1994): 40-50.

MLA (8th ed.) Citation

Leonhard, Hans-Walter. "Was Verursacht Aids?" Psychologie Heute, vol. 21, no. 5, 1994, pp. 40-50.