Hargreaves, R. (2012). How to become a business angel: Practical advice for aspiring investors in unquoted companies. Harriman House Ltd..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Hargreaves, Richard. How to Become a Business Angel: Practical Advice for Aspiring Investors in Unquoted Companies. Hampshire: Harriman House Ltd., 2012.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Hargreaves, Richard. How to Become a Business Angel: Practical Advice for Aspiring Investors in Unquoted Companies. Harriman House Ltd., 2012.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.