%0 Journal Article %A Ya. N. Istomin %A O. A. Pokhotelov %T Nonlinear effects in low-frequency geomagnetic fluctuations %J Doklady Akademii Nauk %D 1978 %P 555-557 %V 238 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1978_238_3_a12/ %G ru %F DAN_1978_238_3_a12