@article{10_4064__27_2_361_366,
     author = {P. Popivanov},
     title = {Wave fronts of solutions of some classes of non-linear partial differential equations},
     journal = {Banach Center Publications},
     pages = {361--366},
     publisher = {mathdoc},
     volume = {27},
     number = {2},
     year = {1992},
     doi = {10.4064/-27-2-361-366},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/-27-2-361-366/}
}