2018CJ/T 51-2018 Standard test method for urban sewage water quality
2004CJ/T 51-2004 Methods for the examination of municipal sewage
1999CJ/T 77-1999 Municipal sewage.Determination of total nitrogen.Distillation and titration method
CJ/T 77-1999 Municipal sewage.Determination of total nitrogen.Distillation and titration method was changed to CJ/T 51-2004 Methods for the examination of municipal sewage.