@article{DAN_1977_234_1_a0,
     author = {A. Dzhuraev},
     title = {On systems of first-order equations of composite type in space},
     journal = {Doklady Akademii Nauk},
     pages = {11--14},
     publisher = {mathdoc},
     volume = {234},
     number = {1},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_234_1_a0/}
}