Heyne, P. T. (1994). The economic way of thinking (7th ed.). MacMillan College Pub. Co. ; Collier Macmillan Canada ; Maxwell Macmillan International.

Heyne, Paul T. The Economic Way of Thinking. 7th ed. New York : Toronto : New York: MacMillan College Pub. Co. ; Collier Macmillan Canada ; Maxwell Macmillan International, 1994.

Heyne, Paul T. The Economic Way of Thinking. 7th ed. MacMillan College Pub. Co. ; Collier Macmillan Canada ; Maxwell Macmillan International, 1994.