I would like a reference for a proof that the Dehn presentation is a presentation of the fundamental group of the knot complement in $\mathbb{S}^{3} $.



Reference for a proof of the Dehn presentation
L.P. Neuwirth, [Knot Groups](http://books.google.co.jp/books?id=hGunUavtc-wC&source=gbs_book_other_versions), Annals of Mathematics Studies, Princeton University Press, 1965.


