@article{AM_2000_152_1_a7,
     author = {Karsten Grove and Wolfgang Ziller},
     title = {Curvature and symmetry of {Milnor} spheres},
     journal = {Annals of mathematics},
     publisher = {mathdoc},
     volume = {152},
     number = {1},
     year = {2000},
     url = {http://geodesic.mathdoc.fr/item/AM_2000_152_1_a7/}
}