1. Effects of cationic surfactants on settling properties of sewage activated sludge;Kakii;J. Ferment. Technol.,1987
2. Effect of calcium ion on sludge characteristics;Kakii;J. Ferment. Technol.,1985
3. Nucleic acid as a component of mucilage in activated sludge;Nishikawa;J. Ferment. Technol.,1974
4. Testing methods for industrial wastewater;Japanese Industrial Standards Committee,1986
5. Toshitsu jikkenho (protein, nucleic acid and enzyme, bessatsu);Anno,1968