@article{IM2_2016_80_1_a6,
     author = {C. Sabbah},
     title = {Differential systems of pure {Gaussian} type},
     journal = {Izvestiya. Mathematics },
     pages = {189--220},
     publisher = {mathdoc},
     volume = {80},
     number = {1},
     year = {2016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2016_80_1_a6/}
}