%0 Journal Article %A N. N. Yanenko %T Invariant differential constraints for hyperbolic systems of quasi-linear equations %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 1961 %P 185-194 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/IVM_1961_3_a19/ %G ru %F IVM_1961_3_a19