On the sparsity issues of interior point methods for quadratic programming. (Working paper of the Laboratory of Operations Research and Decision Systems, (LORDS) WP 98-4.)
Steplengths in infeasible primal-dual interior point algorithms of convex quadratic programming.(Technical report of Imperial College of Science, Technology and Medicine. Department of Computing, DOC 97/7.)
On free variables in interior point methods. (Technical report of Imperial College of Science, Technology and Medicine. Department of Computing, DOC 97/4.)