@article{GDZPPN002059479, title = {Knot Cobordism Groups in Codimension Two.}, journal = {Commentarii mathematici Helvetici}, volume = {44}, year = {1969}, pages = {229-244}, zbl = {0176.22101}, url = {http://dml.mathdoc.fr/item/GDZPPN002059479} }
Levine, J. Knot Cobordism Groups in Codimension Two.. Commentarii mathematici Helvetici, Tome 44 (1969) pp. 229-244. http://gdmltest.u-ga.fr/item/GDZPPN002059479/