@article{3258,
author = {Rubio, G. and J\'odar, L.},
title = {Approximate solutions and error bounds for second order operator differential equations},
journal = {Portugaliae mathematica},
volume = {48},
year = {1991},
pages = {165-177},
zbl = {0773.47031},
mrnumber = {1127119},
language = {en},
url = {http://dml.mathdoc.fr/item/3258}
}
Rubio, G.; Jódar, L. Approximate solutions and error bounds for second order operator differential equations. Portugaliae mathematica, Tome 48 (1991) pp. 165-177. http://gdmltest.u-ga.fr/item/3258/