WASET
    Zenon Chaczko and  Essam Rahali and  Rizwan Tariq,  The Application of Six Sigma to Integration of Computer Based Systems.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2007, vol. 10(10). 517 - 522
    [viewed 20 April 2024]. Available from: https://publications.waset.org/pdf/409.