@article{10_4153_CMB_1972_109_2,
     author = {Rogers, Thomas},
     title = {On {Nagumo's} {Condition}},
     journal = {Canadian mathematical bulletin},
     pages = {609--611},
     year = {1972},
     volume = {15},
     number = {4},
     doi = {10.4153/CMB-1972-109-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1972-109-2/}
}