A Polynomial-Time Approximation Scheme for Weighted Planar Graph TSP.

Sanjeev Arora Michelangelo Grigni David R. Karger Philip N. Klein Andrzej Woloszyn A Polynomial-Time Approximation Scheme for Weighted Planar Graph TSP. 33-41 1998 SODA db/conf/soda/soda98.html#AroraGKKW98