@article{1077474129,
author = {Hartman, Philip},
title = {The $L^2$ -solutions of linear differential equations of second order},
journal = {Duke Math. J.},
volume = {14},
number = {1},
year = {1947},
pages = { 323-326},
language = {en},
url = {http://dml.mathdoc.fr/item/1077474129}
}
Hartman, Philip. The $L^2$ -solutions of linear differential equations of second order. Duke Math. J., Tome 14 (1947) no. 1, pp. 323-326. http://gdmltest.u-ga.fr/item/1077474129/