Ries, A. (1996). Focus: The feature of your company depends on it. Harper Collins Publishers.
Chicago Edition CitationRies, AI. Focus: The Feature of Your Company Depends on It. New York: Harper Collins Publishers, 1996.
ציטוט MLARies, AI. Focus: The Feature of Your Company Depends on It. Harper Collins Publishers, 1996.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.