@article{KUIPM_1989_a1,
     author = {I. B. Badriev and O. V. Pankratova},
     title = {Mixed finite-element method for nonlinear stationary problems of seepage theory},
     journal = {Issledovaniya po Prikladnoi Matematike i Informatike},
     pages = {17--34},
     publisher = {mathdoc},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUIPM_1989_a1/}
}