@article{MAN_1975__217_162752,
     author = {C.McA. Gordon and D.W. Sumners},
     title = {Knotted {Ball} {Pairs} whose {Product} with an {Interval} is {Unknotted.}},
     journal = {Mathematische Annalen},
     pages = {47--52},
     publisher = {mathdoc},
     volume = {217},
     year = {1975},
     zbl = {0293.57010},
     url = {http://geodesic.mathdoc.fr/item/MAN_1975__217_162752/}
}