@article{DAN_1991_316_4_a13,
     author = {E. P. Sobolevskii and P. E. Sobolevskii},
     title = {The commutant method and the coercivity of the {Cauchy} problem},
     journal = {Doklady Akademii Nauk},
     pages = {825--829},
     publisher = {mathdoc},
     volume = {316},
     number = {4},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_316_4_a13/}
}