Eric, O. I. (2007). A study on solid waste management in developing countries: Lessons learned from Malaysia and Nigeria. Fakulti Sains Sosial Dan Kemanusiaan, Universiti Kebangsaan Malaysia.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Eric, Onuegbu Ikenna. A Study on Solid Waste Management in Developing Countries: Lessons Learned from Malaysia and Nigeria. Bangi: Fakulti Sains Sosial Dan Kemanusiaan, Universiti Kebangsaan Malaysia, 2007.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Eric, Onuegbu Ikenna. A Study on Solid Waste Management in Developing Countries: Lessons Learned from Malaysia and Nigeria. Fakulti Sains Sosial Dan Kemanusiaan, Universiti Kebangsaan Malaysia, 2007.
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