2014GOST 13047.20-2014 Nickel. Cobalt. Method for determination of magnesium
2002GOST 13047.20-2002 Nickel. Cobalt. Method for determination of magnesium
1981GOST 13047.17-1981 Nickel. Method for the determination of magnesium
0000 GOST 13047.17-1967
GOST 13047.17-1981 Nickel. Method for the determination of magnesium was changed to GOST 13047.20-2002 Nickel. Cobalt. Method for determination of magnesium.