@article{IVM_1979_4_a4,
     author = {S. I. Piskarev},
     title = {Error estimates in the approximation of semigroups of operators by {Pad\'e} fractions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {33--38},
     year = {1979},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1979_4_a4/}
}