Wanhyun Cho and  Soonja Kang and  Sangkyoon Kim and  Soonyoung Park,  Variational EM Inference Algorithm for Gaussian Process Classification Model with Multiclass and Its Application to Human Action Classification.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2015, vol. 104(8). 2019 - 2025
    [viewed 19 October 2019]. Available from: https://publications.waset.org/pdf/10003023.