@article{CHFMJ_2018_3_4_a1,
     author = {A. I. Kozhanov and A. H. Kodzokov},
     title = {Boundary problems for a class of differential equations  with multiple characteristics},
     journal = {\v{C}el\^abinskij fiziko-matemati\v{c}eskij \v{z}urnal},
     pages = {395--407},
     publisher = {mathdoc},
     volume = {3},
     number = {4},
     year = {2018},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CHFMJ_2018_3_4_a1/}
}