APA
Ferrell R. H., . (1971). America as a World power, 1872-1945. Columbia: University of South Carolina Press.
Chicago
Ferrell Robert H, . 1971. America as a World power, 1872-1945. Columbia: University of South Carolina Press.
Harvard
Ferrell R. H., . (1971). America as a World power, 1872-1945. Columbia: University of South Carolina Press.
MLA
Ferrell Robert H, . America as a World power, 1872-1945. Columbia: University of South Carolina Press. 1971.