@article{10_4153_CMB_1981_063_1,
     author = {Kreith, Kurt and Kusano, Taka\^{s}i},
     title = {Oscillation {Theorems} for {Nonlinear} {Ordinary} {Differential} {Equations} of {Even} {Order}},
     journal = {Canadian mathematical bulletin},
     pages = {409--413},
     year = {1981},
     volume = {24},
     number = {4},
     doi = {10.4153/CMB-1981-063-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1981-063-1/}
}