WASET
    A. Jrade and  N. Markiz and  N. Albelwi,  An Economical Operation Analysis Optimization Model for Heavy Equipment Selection.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2012, vol. 61(1). 146 - 151
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/6378.