Não informado. (2001). Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Zoological Society of Philadelphia.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Philadelphia, Pa: Zoological Society of Philadelphia, 2001.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Zoological Society of Philadelphia, 2001.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.