NBN T 03-412-1983 Aluminium oxide primarily used for the production of aluminium - Determination of vanadium content - ff-Benzoyl-tf-phenylhydroxylamine photometric method
1982NBN T 03-412-1983 Aluminium oxide primarily used for the production of aluminium - Determination of vanadium content - ff-Benzoyl-tf-phenylhydroxylamine photometric method