@article{10_4153_CJM_1971_071_7,
     author = {Kreith, Kurt},
     title = {Disconjugacy {Criteria} for {Nonselfadjoint} {Differential} {Equations} of {Even} {Order}},
     journal = {Canadian journal of mathematics},
     pages = {644--652},
     year = {1971},
     volume = {23},
     number = {4},
     doi = {10.4153/CJM-1971-071-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1971-071-7/}
}