User needs in the postal sector and evaluation of the regulatory framework [documento eletrónico] / Alex Kalevi Dieke...[et al.]
Postal development report 2021 [documento eletrónico] : taking stock of a new reality / Mauro Boffa, Fernão De Borba and Lukasz Piotrowski
Statistique des services postaux 2020 / Union Postale Universelle