@article{IVM_2019_10_a4,
     author = {A. V. Kalinichenko and M. A. Pliev},
     title = {The triangle equality in {Hilbert} $A$-modules},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {38--45},
     publisher = {mathdoc},
     number = {10},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2019_10_a4/}
}