Styl cytowania APA

Black, C. E., & Helmreich, E. C. (1972). Twentieth century Europe: A history. Knopf.

Styl cytowania Chicago

Black, Cyril Edwin, i Ernst Christian Helmreich. Twentieth Century Europe: A History. New York: Knopf, 1972.

Styl cytowania MLA

Black, Cyril Edwin, i Ernst Christian Helmreich. Twentieth Century Europe: A History. Knopf, 1972.