1Mzoughi, T., Davis Herring, S., FoleyJ. T., et al. WebTOP: a 3D interactive system for teaching and learning opticsIJ]. Computers & Educa- tion, 2007,49(1): 110-129.
2Luca Chittaro, Roberto Ranon.Web3D technologies in learning, education and training: Motivations, issues, opportunities. Computers & ,Ed- ucation, 2007, 49: 3-18.