A Loop Theorem for Duality Spaces and Fibred Ribbon Knots. C.McA. Gordon, A.J. Casson (1983) Inventiones mathematicae
Actions de groupes finis sur S 3 : la conjecture de P. A. Smith John W. Morgan (1980/1981) Séminaire Bourbaki
An extension of the Loop theorem and resolutions of generalized 3-manifolds with 0-dimensional singular set. T.L. Thickstun (1984) Inventiones mathematicae