APA

Mabry R. H., Ulbrich H. H., . (1989). Introduction to economic principles. New York: McGraw-Hill.

Chicago

Mabry Rodney H, Ulbrich Holley H, . 1989. Introduction to economic principles. New York: McGraw-Hill.

Harvard

Mabry R. H., Ulbrich H. H., . (1989). Introduction to economic principles. New York: McGraw-Hill.

MLA

Mabry Rodney H, Ulbrich Holley H, . Introduction to economic principles. New York: McGraw-Hill. 1989.