@article{DAN_1964_156_3_a4,
     author = {G. I. Marchuk},
     title = {On the formulation of certain inverse problems},
     journal = {Doklady Akademii Nauk},
     pages = {503--506},
     publisher = {mathdoc},
     volume = {156},
     number = {3},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_156_3_a4/}
}