Kameas, A., I. Mavrommati, and P. Markopoulos,  "Computing in tangible: using artifacts as components of ambient intelligence environments",  In "Ambient Intelligence: The evolution of Technology, Communication and Cognition" (G.Riva, F.Vatalaro, F.Davide and M.Alcaniz,eds): IOS Press, pp. 121-142, 2004.