@article{VMUMM_1982_5_a0,
     author = {Nguyen Thi Thien Hoa},
     title = {An extremal problem for classes of convolutions that do not increase variation},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {3--7},
     publisher = {mathdoc},
     number = {5},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1982_5_a0/}
}