@article{SM_1995_80_1_a2,
     author = {E. V. Radkevich},
     title = {On the spectrum of the~pencil in {the~Verigin--Muskat} problem},
     journal = {Sbornik. Mathematics},
     pages = {33--73},
     publisher = {mathdoc},
     volume = {80},
     number = {1},
     year = {1995},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1995_80_1_a2/}
}