@article{1029000211, author = {Duvall, Paul F.}, title = {Weakly flat spheres.}, journal = {Michigan Math. J.}, volume = {16}, number = {1}, year = {1969}, pages = { 117-124}, language = {en}, url = {http://dml.mathdoc.fr/item/1029000211} }
Duvall, Paul F. Weakly flat spheres.. Michigan Math. J., Tome 16 (1969) no. 1, pp. 117-124. http://gdmltest.u-ga.fr/item/1029000211/