1. Omer AM. Biogas technology and the environment. Regional Energy News, vol. 2, no. 4, Nairobi, Kenya, November, 1996.
2. Sudan energy background; an overview;Omer;Renewable Energy Journal,1998
3. Renewable energy potential and future prospect in Sudan;Omer;Agriculture and Development in Arab World,1996
4. Omer AM. Biomass energy potential and future prospect in Sudan. Khartoum, Sudan, 1999.
5. Anonymous. Chinese or Indian: a comparison. Biogas Newsletter, Nepal, Vol.7, 1979.