APA

Graebner N. A., . (1961). An uncertain tradition: American Secretaries of State in the twentieth century. New York: McGraw-Hill.

Chicago

Graebner Norman A, . 1961. An uncertain tradition: American Secretaries of State in the twentieth century. New York: McGraw-Hill.

Harvard

Graebner N. A., . (1961). An uncertain tradition: American Secretaries of State in the twentieth century. New York: McGraw-Hill.

MLA

Graebner Norman A, . An uncertain tradition: American Secretaries of State in the twentieth century. New York: McGraw-Hill. 1961.