@article{INTG_1981_12_a5,
     author = {A. A. Agrachev and S. A. Vakhrameev},
     title = {Chronological series and the {Cauchy{\textendash}Kovalevskaya} theorem},
     journal = {Itogi Nauki i Tekhniki. Seriya Problemy Geometrii. Trudy Geometricheskogo Seminara},
     pages = {165--189},
     year = {1981},
     volume = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTG_1981_12_a5/}
}