@article{bwmeta1.element.desklight-55230319-c084-4c05-8175-88929b8196dc,
author = {V. Lakshmikantham and S. Leela},
title = {On the method of upper and lower solutions in abstract cones},
journal = {Annales Polonici Mathematici},
volume = {40},
year = {1983},
pages = {159-164},
zbl = {0544.34056},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.desklight-55230319-c084-4c05-8175-88929b8196dc}
}
V. Lakshmikantham; S. Leela. On the method of upper and lower solutions in abstract cones. Annales Polonici Mathematici, Tome 40 (1983) pp. 159-164. http://gdmltest.u-ga.fr/item/bwmeta1.element.desklight-55230319-c084-4c05-8175-88929b8196dc/