@article{IVM_1990_9_a7,
     author = {A. V. Sobolev and V. I. Sobolev},
     title = {Differentiability of {a~Hammerstein} operator and solvability of a~nonlinear {Hammerstein} equation},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {55--62},
     publisher = {mathdoc},
     number = {9},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1990_9_a7/}
}