%0 Journal Article %A A. V. Tropin %A S. I. Spivak %T Approximate analytic integration of the direct kinetic problem %J Sibirskij žurnal industrialʹnoj matematiki %D 2007 %P 135-148 %V 10 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/SJIM_2007_10_4_a14/ %G ru %F SJIM_2007_10_4_a14