@article{1183525016, author = {Gluck, Herman}, title = {Unknotting $S^1$ in $S^4$}, journal = {Bull. Amer. Math. Soc.}, volume = {69}, number = {4}, year = {1963}, pages = { 91-94}, language = {en}, url = {http://dml.mathdoc.fr/item/1183525016} }
Gluck, Herman. Unknotting $S^1$ in $S^4$. Bull. Amer. Math. Soc., Tome 69 (1963) no. 4, pp. 91-94. http://gdmltest.u-ga.fr/item/1183525016/