Locating Facilities on a Network to Minimize Their Average Service Radius. - Davide Bilò; Jörg Derungs; Luciano Gualà; Guido Proietti; Peter Widmayer (ISAAC, 2007)

Approximate Shortest Paths Guided by a Small Index. - Jörg Derungs; Riko Jacob; Peter Widmayer (Algorithmica, 2010)