@article{1102947945, author = {Eaton, W. T.}, title = {A two sided approximation theorem for $2$-spheres.}, journal = {Pacific J. Math.}, volume = {49}, number = {2}, year = {1973}, pages = { 461-485}, language = {en}, url = {http://dml.mathdoc.fr/item/1102947945} }
Eaton, W. T. A two sided approximation theorem for $2$-spheres.. Pacific J. Math., Tome 49 (1973) no. 2, pp. 461-485. http://gdmltest.u-ga.fr/item/1102947945/