Lutz, Frank H, Technische Universität Berlin, Germany

• The Electronic Journal of Combinatorics Volume 20, Issue 3 (2013) - Papers
  Knots in Collapsible and Non-Collapsible Balls
  Abstract  PDF  knots_in_balls__revision.tar.gz  knots_in_balls__revision_v2.tar.gz  knots_in_balls__revision_v2.tar.gz  official source