P. Sawitri and  S. Cdr. Sittha and  T. Kritsana ,  An Improvement of Flow Forming Process for Pressure Vessels by Four Rollers Machine.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2014, vol. 93(9). 1525 - 1529
    [viewed 28 October 2021]. Available from: https://publications.waset.org/pdf/9999246.