@article{TMF_1988_74_3_a1,
     author = {Yu. G. Shondin},
     title = {Quantum-mechanical models in~$R_n$ associated with extensions of the energy operator in {a~Pontryagin} space},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {331--344},
     publisher = {mathdoc},
     volume = {74},
     number = {3},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1988_74_3_a1/}
}