Bita Tadayon and  Nasser Salmasi,  A Flexible Flowshop Scheduling Problem with Machine Eligibility Constraint and Two Criteria Objective Function.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2012, vol. 62(2). 388 - 393
    [viewed 27 November 2021]. Available from: https://publications.waset.org/pdf/4753.