WASET
    T. M. Al Muhareb and  J. Graham-Jones ,  Using Lean Six-Sigma in the Improvement of Service Quality at Aviation Industry: Case Study at the Departure Area in KKIA.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2014, vol. 85(1). 145 - 151
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/9997202.