@article{10_4153_CMB_1972_086_7,
     author = {Beesack, Paul R.},
     title = {On {Sturm's} {Separation} {Theorem}},
     journal = {Canadian mathematical bulletin},
     pages = {481--487},
     year = {1972},
     volume = {15},
     number = {4},
     doi = {10.4153/CMB-1972-086-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1972-086-7/}
}