%0 Journal Article %A E. V. Trifonov %T Families of exact solutions for linear and nonlinear wave equations with a~variable speed of sound and their use in solving initial boundary value problems %J Teoretičeskaâ i matematičeskaâ fizika %D 2017 %P 41-50 %V 192 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2017_192_1_a2/ %G ru %F TMF_2017_192_1_a2