@inproceedings{DATE-1998-HelvigRZ,
	author        = "Christopher S. Helvig and Gabriel Robins and Alexander Zelikovsky",
	booktitle     = "{Proceedings of the Third Conference on Design, Automation and Test in Europe}",
	doi           = "10.1109/DATE.1998.655889",
	pages         = "406--413",
	publisher     = "{IEEE Computer Society}",
	title         = "{Improved Approximation Bounds for the Group Steiner Problem}",
	year          = 1998,
}