@article{DAN_1977_232_1_a2,
     author = {L. I. Kamynin and B. N. Khimchenko},
     title = {On a priori boundary estimates for the solutions of second order equations with nonnegative characteristic form},
     journal = {Doklady Akademii Nauk},
     pages = {16--19},
     publisher = {mathdoc},
     volume = {232},
     number = {1},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_232_1_a2/}
}