@article{IVM_1998_11_a9,
     author = {V. N. Pavlenko and O. V. Ul'yanova},
     title = {The method of upper and lower solutions for elliptic-type equations with discontinuous nonlinearities},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {69--76},
     publisher = {mathdoc},
     number = {11},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1998_11_a9/}
}