@article{DAN_1991_317_3_a1,
     author = {M. K. Balaev},
     title = {On the well-posedness of operator-differential equations of},
     journal = {Doklady Akademii Nauk},
     pages = {526--529},
     publisher = {mathdoc},
     volume = {317},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_317_3_a1/}
}