@article{1028999132, author = {Shapiro, Harold S.}, title = {Some negative theorems of approximation theory.}, journal = {Michigan Math. J.}, volume = {11}, number = {1}, year = {1964}, pages = { 211-217}, language = {en}, url = {http://dml.mathdoc.fr/item/1028999132} }
Shapiro, Harold S. Some negative theorems of approximation theory.. Michigan Math. J., Tome 11 (1964) no. 1, pp. 211-217. http://gdmltest.u-ga.fr/item/1028999132/