@article{IVM_1987_4_a16,
     author = {M. A. Zaretskaya},
     title = {The joint spectrum of a~system of commuting quadratic quantum {Hamiltonians}},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {80--82},
     year = {1987},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1987_4_a16/}
}