%0 Journal Article %A G. N. Petrova %T A hierarchy of characteristic times in geomagnetic field variations %J Doklady Akademii Nauk %D 1989 %P 1346-1350 %V 308 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1989_308_6_a14/ %G ru %F DAN_1989_308_6_a14