@article{RSM_1999__57_1_122470,
     author = {Popivanov, P.R.},
     title = {Local solvability of some classes of linear and nonlinear partial differential equations.},
     journal = {Rendiconti del seminario matematico},
     pages = {11--21},
     publisher = {mathdoc},
     volume = {57},
     number = {1},
     year = {1999},
     zbl = {1008.35001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RSM_1999__57_1_122470/}
}