Provably good routing tree construction with multi-port terminals. - C. Douglass Bateman; Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (ISPD, 1997)

Improved Approximation Bounds for the Group Steiner Problem. - Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (DATE, 1998)

Moving-Target TSP and Related Problems. - Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (ESA, 1998)

New approximation algorithms for routing with multiport terminals. - Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (IEEE Trans. Comput. Aided Des. Integr. Circuits Syst., 2000)

An improved approximation scheme for the Group Steiner Problem. - Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (Networks, 2001)

The moving-target traveling salesman problem. - Christopher S. Helvig; Gabriel Robins; Alexander Zelikovsky (J. Algorithms, 2003)