1. Product Literature;ADI, Inc.,1988
2. Methane Gas Production from Dairy, Poultry and Swine Anaerobic Lagoons;Allen,1976
3. Standard Methods for the Examination of Water and Wastewater;APHA,1981
4. ASAE Standards;ASAE,1985
5. The Universe of U.S. Anaerobic Digesters;Ashworth,1984