1. AIT, (1998).Feasibility study on agricultural use and land application of sewage and nightsoil sludge for Bangkok metropolitan, Asian Institute of Technology, Pathumthani, Thailand.
2. AGSS, (1995) Bio-solid management report., Australian Guidelines for Sewage System.
3. APHA, (1995). Standard methods for examinations of water and wastewater, 19th Ed. American Public Health Association, Washington, DC.
4. ASTM, (1967). International D2974 standard test methods for moisture, ash and organic matter of peat and other organic soils American Society for Testing and Materials. BMA, (1995). Master plan on treatment and disposal of domestic sewage sludge including nightsoil, oil and grease residues for Bangkok metropolitan, Bangkok, Thailand.
5. Carter, M. R. (1993).Soil sampling and methods of analysis. Lewis Publishers, USA.