2014GOST 13047.20-2014 Nickel. Cobalt. Method for determination of magnesium
2002GOST 13047.20-2002 Nickel. Cobalt. Method for determination of magnesium
1980GOST 741.15-1980 Cobalt. Method for the determination of magnesium
0000 GOST 741.15-1969
GOST 741.15-1980 Cobalt. Method for the determination of magnesium was changed to GOST 13047.20-2002 Nickel. Cobalt. Method for determination of magnesium.