@article{GDZPPN001169106, title = {A Simple, Global, Complementary Variational Principle.}, journal = {Numerische Mathematik}, volume = {15}, year = {1970}, pages = {52-57}, url = {http://dml.mathdoc.fr/item/GDZPPN001169106} }
DANIEL, J.W. A Simple, Global, Complementary Variational Principle.. Numerische Mathematik, Tome 15 (1970) pp. 52-57. http://gdmltest.u-ga.fr/item/GDZPPN001169106/