Frey, R. S. (2012). Successful proposal strategies for small businesses: Using knowledge management to win government, private-sector, and international contacts (6th ed.). Artech House.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Frey, Robert S. Successful Proposal Strategies for Small Businesses: Using Knowledge Management to Win Government, Private-sector, and International Contacts. 6th ed. Boston: Artech House, 2012.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Frey, Robert S. Successful Proposal Strategies for Small Businesses: Using Knowledge Management to Win Government, Private-sector, and International Contacts. 6th ed. Artech House, 2012.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.