@article{DAN_1991_318_5_a17,
     author = {Khe Kan Cher},
     title = {Estimation of the solutions of {Darboux--Protter} problems for the
},
     journal = {Doklady Akademii Nauk},
     pages = {1099--1102},
     publisher = {mathdoc},
     volume = {318},
     number = {5},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_318_5_a17/}
}