@article{UFA_2018_10_4_a9,
     author = {S. Ya. Startsev},
     title = {Structure of set of symmetries for  hyperbolic systems of  {Liouville} type and generalized {Laplace} invariants},
     journal = {Ufa mathematical journal},
     pages = {103--110},
     publisher = {mathdoc},
     volume = {10},
     number = {4},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UFA_2018_10_4_a9/}
}