@article{DE_1979_15_2_a1,
     author = {\`E. I. Grudo},
     title = {Representation of fundamental matrices of {Pfaffian} systems with coefficients that have uniform asymptotic expansions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {199--214},
     publisher = {mathdoc},
     volume = {15},
     number = {2},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_2_a1/}
}