Rusliza Ahmad and  Harun Budin,  Stability Analysis of Mutualism Population Model with Time Delay.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    February 2012, vol. 62(2). 151 - 155
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/15765.