@article{MMO_1970_23_a2,
     author = {S. I. Poho\v{z}aev},
     title = {Weakly nonlinear hyperbolic systems},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {61--76},
     publisher = {mathdoc},
     volume = {23},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1970_23_a2/}
}