@article{DAN_1967_172_6_a10,
     author = {M. N. Feller},
     title = {On the equation $\Delta U[x(t)]+P[x(t)]U[x(t)]=0$ in a function space},
     journal = {Doklady Akademii Nauk},
     pages = {1282--1285},
     publisher = {mathdoc},
     volume = {172},
     number = {6},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_172_6_a10/}
}