@article{CMH_1973__48_139562,
     author = {Dieter Erle},
     title = {Some {Non-Linear} {Equivariant} {Sphere} {Bundles}},
     journal = {Commentarii mathematici Helvetici},
     pages = {498--510},
     publisher = {mathdoc},
     volume = {48},
     year = {1973},
     zbl = {0267.55019},
     url = {http://geodesic.mathdoc.fr/item/CMH_1973__48_139562/}
}