MLA

Gruen, John, and Bab Westerveld. Keith Haring : De Biografie. Amsterdam: Meulenhoff, 1991.

APA

Gruen, J., & Westerveld, B. (1991). Keith Haring : de biografie. Amsterdam: Meulenhoff.

Chicago

Gruen, John, and Bab Westerveld. Keith Haring: De Biografie. Amsterdam: Meulenhoff, 1991.