@article{10_4153_CJM_1973_115_0,
     author = {Singh, Bhagat},
     title = {A {Necessary} and {Sufficient} {Condition} for the {Oscillation} of an {Even} {Order} {Nonlinear} {Delay} {Differential} {Equation}},
     journal = {Canadian journal of mathematics},
     pages = {1078--1089},
     year = {1973},
     volume = {25},
     number = {5},
     doi = {10.4153/CJM-1973-115-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-115-0/}
}