توثيق جمعية علم النفس الأمريكية APA (الطبعة السابعة)

United Nations Environment Programme, El-Kholy, O. A., & Tolba, M. K. (1992). The World environment 1972-1992: Two decades of challenge. Published by Chapman & Hall on behalf of the United Nations Environment Programme.

توثيق أسلوب شيكاغو (الطبعة السابعة عشر)

United Nations Environment Programme, O. A. El-Kholy, و Mostafa Kamal Tolba. The World Environment 1972-1992: Two Decades of Challenge. London: Published by Chapman & Hall on behalf of the United Nations Environment Programme, 1992.

توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)

United Nations Environment Programme, et al. The World Environment 1972-1992: Two Decades of Challenge. Published by Chapman & Hall on behalf of the United Nations Environment Programme, 1992.