WASET
    Kawai Nobuaki,  Design of Collaborative Web System: Based on Case Study of PBL Support Systems.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2018, vol. 135(3). 211 - 214
    [viewed 29 March 2024]. Available from: https://publications.waset.org/pdf/10008853.