@article{DAN_1988_299_2_a4,
     author = {L. I. Kamynin},
     title = {A theorem on the interior derivative for a second-order uniformly},
     journal = {Doklady Akademii Nauk},
     pages = {280--283},
     publisher = {mathdoc},
     volume = {299},
     number = {2},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_299_2_a4/}
}