%0 Journal Article %A A. A. Novikov %T The martingale approach in problems on the time of the first crossing of nonlinear boundaries %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1981 %P 130-152 %V 158 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1981_158_a11/ %G ru %F TM_1981_158_a11