@incollection{AST_1973__2-3__229_0,
     author = {Kawai, Takahiro},
     title = {Some applications of micro-local analysis to the global study of linear differential equations},
     booktitle = {Colloque International C.N.R.S. sur les \'equations aux d\'eriv\'ees partielles lin\'eaires},
     series = {Ast\'erisque},
     pages = {229--243},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {2-3},
     year = {1973},
     mrnumber = {391190},
     zbl = {0265.35062},
     language = {en},
     url = {http://www.numdam.org/item/AST_1973__2-3__229_0/}
}