A Note on Cobordism of Surface Links in S 4

Masahico Saito
1991 Proceedings of the American Mathematical Society  
Sato's idea of the asymmetric linking number is used in cyclic branched coverings to give an invariant of the cobordism of embedded surfaces in the 4-sphere.
doi:10.2307/2048428 fatcat:gtac6i6cljbkffmvbznjoamwbi