1. Standard Methods for Examination of Water and Wastewater;APHA,1985
2. Biogas production from crops and organic wastes;Badger;New Zealand J. Sci.,1979
3. Biomethanation of banana trash and coir pith;Deivanai,1992
4. Biogas production from crop residues and aquatic weeds;El-Shinnawi;Resources, Conserv. Recycling,1989
5. Forage fiber analysis (apparatus, reagents, procedures and some applications);Goering,1970