@article{GDZPPN00117388X, title = {Optimization under Nonnegativity Constraints.}, journal = {Numerische Mathematik}, volume = {28}, year = {1977}, pages = {287-294}, zbl = {0348.65062}, url = {http://dml.mathdoc.fr/item/GDZPPN00117388X} }
Mavrides, L.P. Optimization under Nonnegativity Constraints.. Numerische Mathematik, Tome 28 (1977) pp. 287-294. http://gdmltest.u-ga.fr/item/GDZPPN00117388X/