R. Ravi, F. Sibel Salman. Approximation Algorithms for the Traveling Purchaser Problem and its Variants in Network Design. In Jaroslav Nesetril, editor, Algorithms - ESA 99, 7th Annual European Symposium, Prague, Czech Republic, July 16-18, 1999, Proceedings. Volume 1643 of Lecture Notes in Computer Science, pages 29-40, Springer, 1999. [doi]
Abstract is missing.