@article{SM_2013_204_2_a6,
     author = {S. E. Pastukhova},
     title = {Approximations of the operator exponential in a~periodic diffusion problem with drift},
     journal = {Sbornik. Mathematics},
     pages = {280--306},
     publisher = {mathdoc},
     volume = {204},
     number = {2},
     year = {2013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2013_204_2_a6/}
}