APA

Friedrich C. J., . (1967). An introduction to political theory: twelve lectures at Harvard. New York: Harper & Row.

Chicago

Friedrich Carl J, . 1967. An introduction to political theory: twelve lectures at Harvard. New York: Harper & Row.

Harvard

Friedrich C. J., . (1967). An introduction to political theory: twelve lectures at Harvard. New York: Harper & Row.

MLA

Friedrich Carl J, . An introduction to political theory: twelve lectures at Harvard. New York: Harper & Row. 1967.