America in the twentieth century :
a history /
James T. Patterson.

APA Citation

Patterson, J. T. (1994). America in the twentieth century: a history. 4th ed. Fort Worth: Harcourt Brace College Publishers.

MLA Citation

Patterson, James T. America In the Twentieth Century: a History. 4th ed. Fort Worth: Harcourt Brace College Publishers, 1994.

Warning: These citations may not always be complete (especially for serials).