Mohammadhosein Hasanbeig and  Lacra Pavel,  Distributed Coverage Control by Robot Networks in Unknown Environments Using a Modified EM Algorithm.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2017, vol. 127(7). 815 - 823
    [viewed 23 October 2021]. Available from: https://publications.waset.org/pdf/10007337.