2014GOST 13047.21-2014 Nickel. Cobalt. Methods for determination of manganese
2002GOST 13047.21-2002 Nickel. Cobalt. Methods for determination of manganese
1981GOST 13047.18-1981 Nickel. Methods for the determination of manganese
0000 GOST 13047.18-1967
GOST 13047.18-1981 Nickel. Methods for the determination of manganese was changed to GOST 13047.21-2002 Nickel. Cobalt. Methods for determination of manganese.