@article{CM_1973__27_1_49_0, author = {Grove, Karsten and Karcher, Hermann}, title = {On pinched manifolds with fundamental group $\mathbf {Z}_2$}, journal = {Compositio Mathematica}, pages = {49--61}, publisher = {Noordhoff International Publishing}, volume = {27}, number = {1}, year = {1973}, mrnumber = {334244}, zbl = {0266.53032}, language = {en}, url = {http://archive.numdam.org/item/CM_1973__27_1_49_0/} }