@article{1077467206,
author = {Hartman, Philip},
title = {Self-adjoint, non-oscillatory systems of ordinary, second
order, linear differential equations},
journal = {Duke Math. J.},
volume = {24},
number = {1},
year = {1957},
pages = { 25-35},
language = {en},
url = {http://dml.mathdoc.fr/item/1077467206}
}
Hartman, Philip. Self-adjoint, non-oscillatory systems of ordinary, second
order, linear differential equations. Duke Math. J., Tome 24 (1957) no. 1, pp. 25-35. http://gdmltest.u-ga.fr/item/1077467206/