1. Standard Methods For Examination of Water and Wastewater;APHA,1985
2. Biological Reclamation of Solid Wastes;Golueke,1977
3. Compost Engineering: Principles and Practice;Haug,1980
4. Sewage sludge composting process by static pile method;Ishii;Water Sci. Technol.,1991
5. Cluster analysis for analyzing two-way classification data;Lin;Argon. J.,1990