19ª Conferência Postal Rutgers [documento electrónico] : relatório / Carlos Costa, Filipa Silva, Margarida Melo Santos
Universal postal service and competition [documento eletrónico] : experience from Europe / Alex Dieke, Petra Junk, Sonja Thiele
Annual report 2010 [documento eletrónico] / Swiss Post
Statistique des services postaux 2011 / Economic and Regulatory Affairs Directorate of UPU