@article{DAN_1971_198_1_a0,
     author = {A. A. Androshchuk},
     title = {Transformation operators and a uniqueness theorem in the inverse problem for a second order differential equation 
},
     journal = {Doklady Akademii Nauk},
     pages = {9--12},
     publisher = {mathdoc},
     volume = {198},
     number = {1},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_198_1_a0/}
}