@article{MZM_1991_50_6_a7,
     author = {A. A. Lokshin and E. A. Sagomonyan},
     title = {Factorizations of a nonlinear wave equation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {66--70},
     publisher = {mathdoc},
     volume = {50},
     number = {6},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_50_6_a7/}
}