\bibitem{hsnms03} Maria João Nicolau, António Costa, Alexandre
	Santos e Vasco Freitas, {\em Towards Multi-class Based Multicast Routing}
	6th IEEE Int Conf on High Speed Networks and Multimedia Communications
	(HSNMC 2003), Estoril, Portugal, 23-25 July 2003, LNCS 2720,
	pp. 52-61, Ed M. M. Freire et al, Spinger-Verlag Berlin Heidelberg,
	ISBN 3-540-40542-9