Montesinos Amilibia, José MaríaHilden, Hugh MichaelLozano Imízcoz, María Teresa2023-06-212023-06-2119850040-938310.1016/0040-9383(85)90019-9https://hdl.handle.net/20.500.14352/64696The authors construct a cover S3→S3 branched over the "figure eight" knot with preimage the "roman link" and a cover S3→S3 branched over the roman link with preimage containing the Borromean rings L. Since L is universal (i.e. every closed, orientable 3-manifold can be represented as a covering of S3 branched over L) it follows that the "figure eight'' knot is universal, thereby answering a question of Thurston in the affirmative. More generally, it is shown that every rational knot or link which is not toroidal is universalengjournal articlehttp://www.sciencedirect.com/science/article/pii/0040938385900199http://www.sciencedirect.com/restricted access515.162.8Topología1210 Topología