@article{DAN_1989_309_1_a7,
     author = {\'E. V. Nikol'skii},
     title = {Generalized functional-invariant solutions of a second-order multidimensional scalar equation of general form},
     journal = {Doklady Akademii Nauk},
     pages = {38--43},
     publisher = {mathdoc},
     volume = {309},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_309_1_a7/}
}