@article{ZNSL_1998_255_a8,
     author = {A. N. Petrov},
     title = {The monotonicity of average power means},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {140--147},
     publisher = {mathdoc},
     volume = {255},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1998_255_a8/}
}