@article{10_4153_CJM_1976_081_0,
     author = {Kusano, Taka\^{s}i and Naito, Manabu},
     title = {Nonlinear {Oscillation} of {Fourth} {Order} {Differential} {Equations}},
     journal = {Canadian journal of mathematics},
     pages = {840--852},
     year = {1976},
     volume = {28},
     number = {4},
     doi = {10.4153/CJM-1976-081-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-081-0/}
}