@article{10_4153_CMB_1974_069_7,
     author = {Kennedy, E. W.},
     title = {An {Elementary} {Proof} of the {Frobenius} {Factorization} {Theorem} for {Differential} {Equations}},
     journal = {Canadian mathematical bulletin},
     pages = {379--380},
     year = {1974},
     volume = {17},
     number = {3},
     doi = {10.4153/CMB-1974-069-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1974-069-7/}
}