@article{MZM_2009_85_1_a12,
     author = {A. A. Ershov},
     title = {Asymptotic {Expansion} of the {Solution} of a {Second-Order} {Equation}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {134--138},
     publisher = {mathdoc},
     volume = {85},
     number = {1},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2009_85_1_a12/}
}