%0 Journal Article %A S. Sobolev %T Functionally-invariant solutions of wave equation %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1934 %P 259-264 %V 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1934_5_a15/ %G ru %F TM_1934_5_a15