@article{RM_1964_19_5_a21,
     author = {Zh. Ling},
     title = {Asymptotic behaviour of solutions of linear differential equations when perturbation of boundary combined with perturbation of operator},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1964},
     volume = {19},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1964_19_5_a21/}
}