@article{GDZPPN002229706, title = {Optimal nonlinear approximation.}, journal = {Manuscripta mathematica}, volume = {64}, year = {1989}, pages = {469-478}, zbl = {0682.41033}, url = {http://dml.mathdoc.fr/item/GDZPPN002229706} }
DeVore, R.; Howard, R.; Micchelli, C. Optimal nonlinear approximation.. Manuscripta mathematica, Tome 64 (1989) pp. 469-478. http://gdmltest.u-ga.fr/item/GDZPPN002229706/