D. R. Ranasinghearachchi A. K. S. T. Chaminda W. M. D. H. Wanasinghe Thushara Lanka Weerawardane Proposing a New Solution to Reduce the International Roaming Call Cost. 119-130 2016 MONAMI https://doi.org/10.1007/978-3-319-52712-3_9 conf/monami/2016 db/conf/monami/monami2016.html#Ranasinghearachchi16