@article{1028999656,
author = {Meir, A. and Willett, D. and Wong, J. S. W.},
title = {On the asymptotic behavior of the solutions of $x^{\prime\prime}+a(t)x=0$.},
journal = {Michigan Math. J.},
volume = {14},
number = {1},
year = {1967},
pages = { 47-52},
language = {en},
url = {http://dml.mathdoc.fr/item/1028999656}
}
Meir, A.; Willett, D.; Wong, J. S. W. On the asymptotic behavior of the solutions of $x^{\prime\prime}+a(t)x=0$.. Michigan Math. J., Tome 14 (1967) no. 1, pp. 47-52. http://gdmltest.u-ga.fr/item/1028999656/