@article{DE_1994_30_10_a9, author = {E. I. Ganzha}, title = {Higher {Lie--B\"acklund} symmetries of diagonal systems of hydrodynamic type}, journal = {Differencialʹnye uravneni\^a}, pages = {1725--1730}, publisher = {mathdoc}, volume = {30}, number = {10}, year = {1994}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1994_30_10_a9/} }