@article{DAN_1993_330_1_a6,
     author = {V. E. Shemarulin},
     title = {Higher symmetry algebra structure and local equivalences of {Euler--Darboux} equations},
     journal = {Doklady Akademii Nauk},
     pages = {24--27},
     publisher = {mathdoc},
     volume = {330},
     number = {1},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1993_330_1_a6/}
}