Ries, A. (1996). Focus: The feature of your company depends on it. Harper Collins Publishers.
Styl cytowania ChicagoRies, AI. Focus: The Feature of Your Company Depends on It. New York: Harper Collins Publishers, 1996.
Styl cytowania MLARies, AI. Focus: The Feature of Your Company Depends on It. Harper Collins Publishers, 1996.
Uwaga: Te cytaty mogą odróżniać się od wytycznej twojego fakultetu..