@article{DAN_1957_113_5_a3,
     author = {M. I. Vishik and L. A. Lyusternik},
     title = {On some even order elliptic equations containing small parameters in higher derivative terms and degenerating},
     journal = {Doklady Akademii Nauk},
     pages = {962--965},
     year = {1957},
     volume = {113},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_113_5_a3/}
}