@article {Katsianis2007,
	title = {Design and implementation approaches for location-based, tourism-related services},
	journal = {Information and Communication Technologies in Support of the Tourism Industry},
	year = {2007},
	pages = {114-161},
	author = {Kakaletris, G. and Varoutas, D and Katsianis, D and Sphicopoulos, T}
}
