https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 A model for enhancing presence handling in instant messaging https://commons.ru.ac.za/vital/access/manager/Repository/vital:9774 Wed 12 May 2021 22:47:41 SAST ]]> The cost of free instant messaging: an attack modelling perspective https://commons.ru.ac.za/vital/access/manager/Repository/vital:9797 Thu 13 May 2021 03:54:06 SAST ]]>