Rajesh Karunamurthy Ferhat Khendek Roch H. Glitho Using web services for presence-based application development. 167-197 2006 2 IJWGS 2 http://dx.doi.org/10.1504/IJWGS.2006.010806 db/journals/ijwgs/ijwgs2.html#KarunamurthyKG06