@article{MZM_1971_9_1_a3,
     author = {Yu. V. Pokornyi},
     title = {Inequality for second characteristic values of positive operators of certain classes},
     journal = {Matemati\v{c}eskie zametki},
     pages = {27--33},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_9_1_a3/}
}