TY  - JOUR
AU  - V. Lakshmikantham
AU  - S. Leela
TI  - On the method of upper and lower solutions in abstract cones
JO  - Annales Polonici Mathematici
PY  - 1983
SP  - 159
EP  - 164
VL  - 42
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/ap-42-1-159-164/
DO  - 10.4064/ap-42-1-159-164
LA  - en
ID  - 10_4064_ap_42_1_159_164
ER  -