@article{1102785281,
author = {Elias, Uri},
title = {Necessary conditions and sufficient conditions for disfocality and disconjugacy of a differential equation.},
journal = {Pacific J. Math.},
volume = {85},
number = {2},
year = {1979},
pages = { 379-397},
language = {en},
url = {http://dml.mathdoc.fr/item/1102785281}
}
Elias, Uri. Necessary conditions and sufficient conditions for disfocality and disconjugacy of a differential equation.. Pacific J. Math., Tome 85 (1979) no. 2, pp. 379-397. http://gdmltest.u-ga.fr/item/1102785281/