VOSYLIUS, V.; PAULIUKAS, D. QoS Analysis of IMS Signalling in UMTS Networks. Elektronika ir Elektrotechnika, [S. l.], v. 105, n. 9, p. 19-22, 2010. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/9161. Acesso em: 4 dec. 2021.