%0 Journal Article %A V. I. Skobelkin %T Variation principles in determining the main characteristics of a ferromagnetic by the calculation of its hysteresis loop %J Doklady Akademii Nauk %D 1960 %P 1012-1014 %V 130 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1960_130_5_a15/ %G ru %F DAN_1960_130_5_a15