@article{ASNSP_1975_4_2_3_479_0, author = {Kaufman, Robert}, title = {Approximation of smooth functions and covering properties of sets}, journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze}, pages = {479--481}, publisher = {Scuola normale superiore}, volume = {Ser. 4, 2}, number = {3}, year = {1975}, zbl = {0325.41018}, mrnumber = {379775}, language = {en}, url = {http://www.numdam.org/item/ASNSP_1975_4_2_3_479_0/} }