Changjin Xu,  Periodic Solutions for a Two-prey One-predator System on Time Scales.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    December 2011, vol. 60(12). 1848 - 1853
    [viewed 10 May 2024]. Available from: https://publications.waset.org/pdf/5256.