Khalide Jbilou,  Approximate Solutions to Large Stein Matrix Equations.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    October 2012, vol. 70(10). 1380 - 1384
    [viewed 22 February 2020]. Available from: https://publications.waset.org/pdf/5480.