APA

Buchanan W., . (1988). Understanding political variables. New York: Macmillan Publishing Co.

Chicago

Buchanan William, . 1988. Understanding political variables. New York: Macmillan Publishing Co.

Harvard

Buchanan W., . (1988). Understanding political variables. New York: Macmillan Publishing Co.

MLA

Buchanan William, . Understanding political variables. New York: Macmillan Publishing Co. 1988.