@article{CMH_1974__49_139582,
     author = {Shing Tung Yau and H. Blaine jr. Lawson},
     title = {Scalar {Curvature,} {Non-Abelian} {Group} {Actions,} and the {Degree} of {Symmetry} of {Exotic} {Spheres}},
     journal = {Commentarii mathematici Helvetici},
     pages = {232--244},
     publisher = {mathdoc},
     volume = {49},
     year = {1974},
     zbl = {0297.57016},
     url = {http://geodesic.mathdoc.fr/item/CMH_1974__49_139582/}
}