%0 Journal Article %A N. E. Tsapenko %T New formulas for the approximate solution of a one-dimensional wave equation %J Differencialʹnye uravneniâ %D 1989 %P 1941-1946 %V 25 %N 11 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1989_25_11_a15/ %G ru %F DE_1989_25_11_a15