WASET
    Shyue-Ran Li and  Kuohsiang Chen,  3D Definition for Human Smiles.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2009, vol. 30(6). 1544 - 1549
    [viewed 20 April 2024]. Available from: https://publications.waset.org/pdf/209.