@article{MMO_1953_2_a0,
     author = {V. A. Marchenko},
     title = {Some questions of the theory of one-dimensional linear differential operators of the second {order.~II}},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {3--83},
     year = {1953},
     volume = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1953_2_a0/}
}