@article{DAN_1968_178_2_a0,
     author = {A.-K. Yu. Abazaliev},
     title = {Characteristic coefficients of two-dimensional distributions and their applications},
     journal = {Doklady Akademii Nauk},
     pages = {263--266},
     publisher = {mathdoc},
     volume = {178},
     number = {2},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1968_178_2_a0/}
}