Elina Bakhtieva,  Digital Marketing Maturity Models: Overview and Comparison.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2017, vol. 125(5). 1140 - 1148
    [viewed 20 April 2024]. Available from: https://publications.waset.org/pdf/10006981.