@book{MSMF_1995_2_63__R1_0,
     author = {Kashiwara, Masaki},
     title = {Algebraic study of systems of partial differential equations},
     series = {M\'emoires de la Soci\'et\'e Math\'ematique de France},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {63},
     year = {1995},
     doi = {10.24033/msmf.377},
     zbl = {0877.35003},
     language = {en},
     url = {http://archive.numdam.org/item/MSMF_1995_2_63__R1_0/}
}