@article{GDZPPN001169955, title = {Ritz Approximations to Two-Dimensional Boundary Value Problems.}, journal = {Numerische Mathematik}, volume = {18}, year = {1971}, pages = {171-181}, zbl = {0213.17002}, url = {http://dml.mathdoc.fr/item/GDZPPN001169955} }
Hall, C.A.; Carlson, R.E. Ritz Approximations to Two-Dimensional Boundary Value Problems.. Numerische Mathematik, Tome 18 (1971) pp. 171-181. http://gdmltest.u-ga.fr/item/GDZPPN001169955/