MLA

Friedrich, Dorothee, and Wolfgang Heckmann. Aids In Europe - the Behavioural Aspect : Vol 1: General Aspects. Berlin: SIGMA, 1995.

APA

Friedrich, D., & Heckmann, W. (1995). Aids in Europe - the behavioural aspect : vol 1: general aspects. Berlin: SIGMA.

Chicago

Friedrich, Dorothee, and Wolfgang Heckmann. Aids In Europe - the Behavioural Aspect: Vol 1: General Aspects. Berlin: SIGMA, 1995.