Parviz Alinezhad and  Ali Sanati and  Koorosh Naser Momtahen,  Computer Aided Design of Reshaping Process of Circular Pipes into Square Pipes.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    July 2009, vol. 31(7). 468 - 472
    [viewed 27 February 2020]. Available from: https://publications.waset.org/pdf/5773.