@article{IVM_1975_6_a8,
     author = {A. D. Lyashko and M. M. Karchevskii},
     title = {The solution of certain nonlinear problems of filtration theory},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {73--81},
     year = {1975},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1975_6_a8/}
}