Heppell, M. How to Have a Brilliant Life: Put a little bit more in. Get so much more out (2.). Pearson Education UK.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Heppell, Michael. How to Have a Brilliant Life: Put a Little Bit More in. Get so Much More Out. 2. Pearson Education UK.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Heppell, Michael. How to Have a Brilliant Life: Put a Little Bit More in. Get so Much More Out. 2. Pearson Education UK.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.