Elkind, D. (2007). The power of play: How spontaneous, imaginative activities lead to happier, healthier children. Da Capo Lifelong.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Elkind, David. The Power of Play: How Spontaneous, Imaginative Activities Lead to Happier, Healthier Children. Cambridge, MA: Da Capo Lifelong, 2007.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Elkind, David. The Power of Play: How Spontaneous, Imaginative Activities Lead to Happier, Healthier Children. Da Capo Lifelong, 2007.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.