@article{GDZPPN002064278, title = {The equivariant Dehn's lemma and loop theorem.}, journal = {Commentarii mathematici Helvetici}, volume = {56}, year = {1981}, pages = {225-239}, zbl = {0469.57005}, url = {http://dml.mathdoc.fr/item/GDZPPN002064278} }
Yau, Shing-Tung; Meeks III, W.H. The equivariant Dehn's lemma and loop theorem.. Commentarii mathematici Helvetici, Tome 56 (1981) pp. 225-239. http://gdmltest.u-ga.fr/item/GDZPPN002064278/