Jamshaid ur Rehman and  Shahida Wizarat,  Cost and Productivity Experiences of Pakistan with Aggregate Learning Curve.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2010, vol. 39(3). 280 - 287
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/7272.