@article{DAN_1964_156_6_a13,
     author = {L. I. Yakut},
     title = {Theorems of {Lax} for non-linear evolutionary equations},
     journal = {Doklady Akademii Nauk},
     pages = {1304--1307},
     publisher = {mathdoc},
     volume = {156},
     number = {6},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_156_6_a13/}
}