Yoonjung An and  Yongtae Park,  A Framework for Designing Complex Product- Service Systems with a Multi-Domain Matrix.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2015, vol. 99(3). 758 - 761
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/10000960.