@article{MZM_1989_46_6_a16,
     author = {A. V. Krylov},
     title = {Interior averaging of first-order partial differential systems},
     journal = {Matemati\v{c}eskie zametki},
     pages = {112--113},
     publisher = {mathdoc},
     volume = {46},
     number = {6},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1989_46_6_a16/}
}