@article{VMUMM_1989_1_a9,
     author = {N. I. Derevyanko},
     title = {Approximation of the values of some functions},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {45--49},
     publisher = {mathdoc},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1989_1_a9/}
}