2014GOST 13047.21-2014 Nickel. Cobalt. Methods for determination of manganese
2002GOST 13047.21-2002 Nickel. Cobalt. Methods for determination of manganese
1980GOST 741.7-1980 Cobalt. Methods for the determination of manganese
0000 GOST 741.7-1969
GOST 741.7-1980 Cobalt. Methods for the determination of manganese was changed to GOST 13047.21-2002 Nickel. Cobalt. Methods for determination of manganese.