@article{1183532223, author = {Singer, William M.}, title = {Extension theory for connected Hopf algebras}, journal = {Bull. Amer. Math. Soc.}, volume = {76}, number = {4}, year = {1970}, pages = { 1095-1099}, language = {en}, url = {http://dml.mathdoc.fr/item/1183532223} }
Singer, William M. Extension theory for connected Hopf algebras. Bull. Amer. Math. Soc., Tome 76 (1970) no. 4, pp. 1095-1099. http://gdmltest.u-ga.fr/item/1183532223/