@article{IVM_1996_8_a0,
     author = {Yu. G. Abakumov and V. E. Banine},
     title = {On some classes of operators, including the class of positive operators},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {3--5},
     year = {1996},
     number = {8},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1996_8_a0/}
}