Babak H. Tabrizi and  Seyed Farid Ghaderi,  An Improved GA to Address Integrated Formulation of Project Scheduling and Material Ordering with Discount Options.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2016, vol. 114(6). 2189 - 2192
    [viewed 19 March 2024]. Available from: https://publications.waset.org/pdf/10005097.