@article{1103037532,
author = {Barrett, John H.},
title = {Disconjugacy of a self-adjoint differential equation of the fourth order.},
journal = {Pacific J. Math.},
volume = {11},
number = {4},
year = {1961},
pages = { 25-37},
language = {en},
url = {http://dml.mathdoc.fr/item/1103037532}
}
Barrett, John H. Disconjugacy of a self-adjoint differential equation of the fourth order.. Pacific J. Math., Tome 11 (1961) no. 4, pp. 25-37. http://gdmltest.u-ga.fr/item/1103037532/