@article{MMO_1953_2_a2,
     author = {A. M. Molchanov},
     title = {On conditions for discreteness of the spectrum of self-adjoint differential equations of the second order},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {169--199},
     publisher = {mathdoc},
     volume = {2},
     year = {1953},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1953_2_a2/}
}