1. Standard Methods for the Examination of Water and Wastewater;APHA,1982
2. Studies in Organic Chemistry, Volume 4: Gas Hydrates;Bereca,1983
3. Natural freeze dewatering of aluminum hydroxide sludges;Farrell;J. Am. Wat. Wks Ass.,1970
4. Freezing method for conditioning activated sludge;Katz,1967
5. Principles and techniques for conditioning waste activated sludge;Khan,1974