NBN T 03-448-1983 Cryolite, natural and artificial, and aluminium fluoride for industrial use -Determination of phosphorus content - Reduced molybdophosphate photometric method
1982NBN T 03-448-1983 Cryolite, natural and artificial, and aluminium fluoride for industrial use -Determination of phosphorus content - Reduced molybdophosphate photometric method