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@article{MS_1950__69_1_a1, author = {{\CYRI}.{\CYRS}. {\CYRG}{\cyrr}{\cyra}{\cyrd}{\cyrsh}{\cyrt}{\cyre}{\cyrishrt}{\cyrn}}, title = {{\CYRL}{\cyri}{\cyrn}{\cyre}{\cyrishrt}{\cyrn}{\cyrery}{\cyre} {\cyru}{\cyrr}{\cyra}{\cyrv}{\cyrn}{\cyre}{\cyrn}{\cyri}{\cyrya} {\cyrs} {\cyrp}{\cyre}{\cyrr}{\cyre}{\cyrm}{\cyre}{\cyrn}{\cyrn}{\cyrery}{\cyrm}{\cyri} {\cyrk}{\cyro}{\cyrerev}{\cyrf}{\cyrf}{\cyri}{\cyrc}{\cyri}{\cyre}{\cyrn}{\cyrt}{\cyra}{\cyrm}{\cyri} {\cyri} {\cyrm}{\cyra}{\cyrl}{\cyrery}{\cyrm}{\cyri} {\cyrp}{\cyra}{\cyrr}{\cyra}{\cyrm}{\cyre}{\cyrt}{\cyrr}{\cyra}{\cyrm}{\cyri} {\cyrp}{\cyrr}{\cyri} {\cyrs}{\cyrt}{\cyra}{\cyrr}{\cyrsh}{\cyri}{\cyrh} {\cyrp}{\cyrr}{\cyro}{\cyri}{\cyrz}{\cyrv}{\cyro}{\cyrd}{\cyrn}{\cyrery}{\cyrh}}, journal = {Matemati\v{c}eskij sbornik}, pages = {47--68}, publisher = {mathdoc}, volume = {69}, number = {1}, year = {1950}, zbl = {0041.05801}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MS_1950__69_1_a1/} }
И.С. Градштейн. Линейные уравнения с переменными коэффициентами и малыми параметрами при старших производных. Matematičeskij sbornik, Tome 69 (1950) no. 1, pp. 47-68. http://geodesic.mathdoc.fr/item/MS_1950__69_1_a1/