@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/