1. Ekahau, 2003, Ekahau Positioning Engine for WLAN based navigation; http://www.ekahau.com/products/positioningengine/features.html ; (June 4, 2003)
2. Pigneur, Y., 2002, An Ontology for m-business models, in S. Spaccapietra et al. (Eds.) Conceptual Modeling-ER 2002, Tampere, Lecture Notes in Computer Science, 2503, October 2002
3. Spinney, J., 2003, Cellular-to-WiFi Handoff, Micro-LBS and the Symbiotic power of Location, in “Java Location Services”; http://www.jlocationservices.com/ ; (June 3, 2003)
4. T-Mobile, 2004. 3GSM World Congress: T-Mobile announces broadband mobile launch; www.t-mobile.net/CDA/integrated_network_set_to_launch,20,,newsid-2685,en.html?w=890&h=577; (April 29, 2004)