Orestis Κ. Efthymiou and  Stavros T. Ponis,  Current Status of Industry 4.0 in Material Handling Automation and In-house Logistics.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2019, vol. 154(10). 1370 - 1374
    [viewed 12 November 2019]. Available from: https://publications.waset.org/pdf/10010833.