Kiyohiro Yamazaki,  Competitive Advantages of a Firm without Fundamental Technology: A Case Study of Sony, Casio and Nintendo.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2016, vol. 120(12). 3990 - 4000
    [viewed 18 October 2019]. Available from: https://publications.waset.org/pdf/10006357.