Isolated critical points of mappings from R4 to R2 and a natural splitting of the Milnor number of a classical fibered link. Part I: Basic theory; examples.
Isolated fixed points of circle actions on 4-manifolds.
Isometries of systolic spaces
We provide a classification of isometries of systolic complexes corresponding to the classification of isometries of CAT(0)-spaces. We prove that any isometry of a systolic complex either fixes the barycentre of some simplex (elliptic case) or stabilizes a thick geodesic (hyperbolic case). This leads to an alternative proof of the fact that finitely generated abelian subgroups of systolic groups are undistorted.
Isomorphisms and Peripheral Structure of Knot Groups.
Isoperimetric inequalities and the homology of groups.