Ziefert, H., & Bolam, E. (2014). Does a hippo go to the doctor?: Think about how everyone keeps healthy ([New edition].). Blue Apple Books.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ziefert, Harriet, و Emily Bolam. Does a Hippo Go to the Doctor?: Think About How Everyone Keeps Healthy. [New edition]. Maplewood, NJ: Blue Apple Books, 2014.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Ziefert, Harriet, و Emily Bolam. Does a Hippo Go to the Doctor?: Think About How Everyone Keeps Healthy. [New edition]. Blue Apple Books, 2014.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.