@article{IVM_2013_9_a10,
     author = {S. Ya. Serovaiskii},
     title = {An optimal control problem for a~nonlinear elliptic equation with a~phase constraint and state variation},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {81--86},
     publisher = {mathdoc},
     number = {9},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2013_9_a10/}
}