Implementing Mobile Environments using Learning Objects: The Athabasca University Digital Reading Room. - Rory McGreal; Billy Cheung; Tony Tin; Steve Schafer (WMTE, 2005)

The Effect of Colour and Transparency on the Perception of Overlaid Grids. - Lyn Bartram; Billy Cheung; Maureen C. Stone (IEEE Trans. Vis. Comput. Graph., 2011)