Architecture for a service-oriented and convergent charging in 3G mobile networks and beyond, R. Kühne, U. Reimer, M.Schläger, F.Dressler, C. Fan, A. Fessi, A. Klenk, G. Carle, "Archived copy"(PDF). Archived from the original(PDF) on 2011-07-19. Retrieved 2009-06-25.{{cite web}}: CS1 maint: archived copy as title (link)
Architecture for a service-oriented and convergent charging in 3G mobile networks and beyond, R. Kühne, U. Reimer, M.Schläger, F.Dressler, C. Fan, A. Fessi, A. Klenk, G. Carle, "Archived copy"(PDF). Archived from the original(PDF) on 2011-07-19. Retrieved 2009-06-25.{{cite web}}: CS1 maint: archived copy as title (link)