@article{DAN_1975_224_6_a6,
     author = {E. I. Pustyl'nik},
     title = {On subordination relations for concave functions of selfadjoint operators},
     journal = {Doklady Akademii Nauk},
     pages = {1264--1267},
     publisher = {mathdoc},
     volume = {224},
     number = {6},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1975_224_6_a6/}
}