@article{ZVMMF_2014_54_5_a6,
     author = {A. B. Kostin},
     title = {Counterexamples in inverse problems for parabolic, elliptic, and hyperbolic equations},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {779--792},
     publisher = {mathdoc},
     volume = {54},
     number = {5},
     year = {2014},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_2014_54_5_a6/}
}