@article{CMH_1990__65_3_140180,
     author = {Ernst A. Ruh and Maung Min-O},
     title = {L2 - {Curvature} pinching.},
     journal = {Commentarii mathematici Helvetici},
     pages = {36--51},
     publisher = {mathdoc},
     volume = {65},
     number = {3},
     year = {1990},
     zbl = {0704.53031},
     url = {http://geodesic.mathdoc.fr/item/CMH_1990__65_3_140180/}
}