A. H. Hendry and  H. S. Mogindol,  Applying WILSERV in Measuring Visitor Satisfaction at Sepilok Orangutan Rehabilitation Centre (SORC).   journal   = {International Journal of Social and Business Sciences}, [online]. World Academy of Science, Engineering and Technology.
    September 2017, vol. 128(8). 2186 - 2190
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/10008112.