Twentieth century Europe,
a history,
by C. E. Black and E. C. Helmreich.
APA Citation
Black, C. Edwin., Helmreich, E. Christian. (1959). Twentieth century Europe: a history. 2d ed., rev. New York: Knopf.
MLA Citation
Black, Cyril Edwin, 1915-1989, and Ernst Christian Helmreich. Twentieth Century Europe: a History. 2d ed., rev. New York: Knopf, 1959.
Warning: These citations may not always be complete (especially for serials).