Xuan Qi and  Changzhi Zhao,  Calculus-based Runtime Verification.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2009, vol. 34(10). 2369 - 2373
    [viewed 21 April 2021]. Available from: https://publications.waset.org/pdf/15100.