Perry, J. S. (1996). Understanding our planet: An overview of the major scientific activities of ICSU and its partners that address global environmental change (Second edition.). International Council of Scientific Unions.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Perry, John S. Understanding Our Planet: An Overview of the Major Scientific Activities of ICSU and Its Partners That Address Global Environmental Change. Second edition. Paris, France: International Council of Scientific Unions, 1996.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Perry, John S. Understanding Our Planet: An Overview of the Major Scientific Activities of ICSU and Its Partners That Address Global Environmental Change. Second edition. International Council of Scientific Unions, 1996.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.