@article{05875529,
title = {A property of the defining equations for the Lie algebra in the group classification problem for wave equations.},
journal = {Sibirskij Matematicheskij Zhurnal},
volume = {50},
year = {2009},
pages = {647-668},
zbl = {1224.35289},
language = {en},
url = {http://dml.mathdoc.fr/item/05875529}
}
Khabirov, S.V. A property of the defining equations for the Lie algebra in the group classification problem for wave equations.. Sibirskij Matematicheskij Zhurnal, Tome 50 (2009) pp. 647-668. http://gdmltest.u-ga.fr/item/05875529/