@article{TMF_1988_75_1_a1,
     author = {F. Kh. Mukminov},
     title = {On straightening the characteristics of a~quasilinear second-order equation},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {18--25},
     year = {1988},
     volume = {75},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1988_75_1_a1/}
}