@article{DAN_1963_150_3_a5,
     author = {B. M. Levitan},
     title = {Determination of the {Sturm--Liouville} differential equation by two spectra},
     journal = {Doklady Akademii Nauk},
     pages = {474--476},
     publisher = {mathdoc},
     volume = {150},
     number = {3},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_150_3_a5/}
}