@article {18130,
	title = {Solving NP-hard problems on graphs that are almost trees and an application to facility location problems},
	journal = {Journal of the ACM (JACM)},
	volume = {31},
	year = {1984},
	month = {1984///},
	pages = {459 - 473},
	author = {Gurevich,Y. and Stockmeyer,L. and Vishkin, Uzi}
}
