Khoo Eng Tat Adrian David Cheok Ta Huynh Duy Nguyen Zhigeng Pan Age invaders: social and physical inter-generational mixed reality family entertainment. 3-16 2008 12 Virtual Reality 1 http://dx.doi.org/10.1007/s10055-008-0083-0 db/journals/vr/vr12.html#TatCNP08