APA

Porter M. E., . (1985). Competitive advantage: creating and sustaining superior performance. New York: Free Press.

Chicago

Porter Michael E, . 1985. Competitive advantage: creating and sustaining superior performance. New York: Free Press.

Harvard

Porter M. E., . (1985). Competitive advantage: creating and sustaining superior performance. New York: Free Press.

MLA

Porter Michael E, . Competitive advantage: creating and sustaining superior performance. New York: Free Press. 1985.