Kejun Zhuang, Periodicity for a Semi–Ratio–Dependent Predator–Prey System with Delays on Time Scales. journal = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology. July 2010, vol. 43(7). 780 - 783 [viewed 20 September 2024]. Available from: https://publications.waset.org/pdf/9158.