@article{DE_1966_2_7_a5,
     author = {S. G. Krein and G. I. Laptev},
     title = {Correctness of boundary value problems for a differential equation of the second order in a {Banach} space. {II}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {919--926},
     publisher = {mathdoc},
     volume = {2},
     number = {7},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1966_2_7_a5/}
}