1. Biogas Production by Anaerobic Digestion of Vegetable Matter;Gamboni,1982
2. Anaerobic Fermentation of Refuse;De Baere,1987
3. Future trends in digester design;Jewell,1979
4. Other treatment and disposal methods;World Health Organization,1991
5. Energy for Bioconversion of Waste Materials;De Renzo,1977