@article{GDZPPN002099837, title = {A Loop Theorem for Duality Spaces and Fibred Ribbon Knots.}, journal = {Inventiones mathematicae}, volume = {74}, year = {1983}, pages = {119-138}, zbl = {0538.57003}, url = {http://dml.mathdoc.fr/item/GDZPPN002099837} }
Gordon, C.McA.; Casson, A.J. A Loop Theorem for Duality Spaces and Fibred Ribbon Knots.. Inventiones mathematicae, Tome 74 (1983) pp. 119-138. http://gdmltest.u-ga.fr/item/GDZPPN002099837/