1. Azhari, P., Faraby, N., Rossmann, A., Steimel, B., Wichmann, K.: Digital Transformation Report 2014 (2014). https://www.wiwo.de/downloads/10773004/1/dta_report_neu.pdf. Accessed 11 Mar 2020
2. Baines, T.S., Lightfoot, H.W., Benedettini, O., Kay, J.M.: The servitization of manufacturing. JMTM 20(5), 547–567 (2009). https://doi.org/10.1108/17410380910960984
3. Berghaus, S., Back, A., Kaltenrieder, B.: Digital maturity & transformation report (2017). https://crosswalk.ch/digital-maturity-and-transformation-report. Accessed 16 Jan 2020
4. Birkel, H., Veile, J., Müller, J., Hartmann, E., Voigt, K.-I.: Development of a risk framework for industry 4.0 in the context of sustainability for established manufacturers. Sustainability 11(2), 384 (2019). https://doi.org/10.3390/su11020384
5. Centobelli, P., Cerchione, R., Esposito, E., Raffa, M.: Digital marketing in small and medium enterprises: the impact of web-based technologies. Adv. Sci. Lett. 22(5), 1473–1476 (2016). https://doi.org/10.1166/asl.2016.6648