@article{IVM_1979_12_a11,
     author = {P. A. Ibetov},
     title = {Gevrey operator classes with respect to a~hypoelliptic operator},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {67--69},
     publisher = {mathdoc},
     number = {12},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1979_12_a11/}
}