@article{ASNSP_2001_4_30_2_465_0,
     author = {Nagata, Makoto},
     title = {A generalization of the sizes of differential equations and its applications to $G$-function theory},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {465--497},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 30},
     number = {2},
     year = {2001},
     mrnumber = {1895719},
     zbl = {1010.12007},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_2001_4_30_2_465_0/}
}