Moraliyska, Monika, and Albena Antonova. “Preparing for Industry 4.0 and Digital Transformations In SMEs. European and National Aspects”. UNWE Yearbook, no. 1 (December 27, 2018): 191–207. Accessed July 22, 2026. https://bjiep.e-dnrs.org/index.php/yb/article/view/5983.