%0 Journal Article %A B. P. Bogoslovskii %T The nonstationary singularities of a certain class of nonlinear equations %J Differencialʹnye uravneniâ %D 1972 %P 1919-1926 %V 8 %N 11 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1972_8_11_a0/ %G ru %F DE_1972_8_11_a0