As leis do comércio electrónico : regime jurídico da assinatura digital e da factura electrónica / Manuel Lopes Rocha ...[et.al.]
Droit européen des télécommunications : l'organisation des marchés / Paul Nihoul
Mobile telecommunications : standards, regulation and applications / Rudi Bekkers, Jan Smits
Third generation mobile communication system / ed. Ramjee Prasad, Werner Mohr, Walter Konhäuser