@article{DAN_1991_321_2_a3,
     author = {V. G. Romanov},
     title = {Uniqueness theorems in inverse problems for some second-order},
     journal = {Doklady Akademii Nauk},
     pages = {254--257},
     publisher = {mathdoc},
     volume = {321},
     number = {2},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_321_2_a3/}
}