Παραπομπή APA

Ries, A. (1996). Focus: The feature of your company depends on it. Harper Collins Publishers.

Παραπομπή Chicago Style

Ries, AI. Focus: The Feature of Your Company Depends on It. New York: Harper Collins Publishers, 1996.

Παραπομπή MLA

Ries, AI. Focus: The Feature of Your Company Depends on It. Harper Collins Publishers, 1996.