@article{ARM_1971__7_1_a1,
     author = {Karim, Rahmi Ibrahim Ibrahim Abdel},
     title = {On the exceptional case in systems of non-linear differential equations},
     journal = {Archivum mathematicum},
     pages = {9--20},
     publisher = {mathdoc},
     volume = {07},
     number = {1},
     year = {1971},
     mrnumber = {0304775},
     zbl = {0243.34069},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1971__7_1_a1/}
}