@article{IVM_2002_1_a3,
     author = {S. A. Gusarenko},
     title = {On conditions for the positive-definiteness of operators in a {Hilbert} space},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {17--20},
     publisher = {mathdoc},
     number = {1},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2002_1_a3/}
}