Cita APA (7a ed.)
Gregory, R. (1971). The origins of American intervention in the First World War ([1st ed.].). Norton.
Cita Chicago Style (17a ed.)
Gregory, Ross. The Origins of American Intervention in the First World War. [1st ed.]. New York: Norton, 1971.
Cita MLA (9a ed.)
Gregory, Ross. The Origins of American Intervention in the First World War. [1st ed.]. Norton, 1971.
Precaución: Estas citas no son 100% exactas.