Nenov, Nicholay Hristov. “INDUSTRY 4.0 – ADVANTAGES ANDCHALLENGES IN THE REPUBLIC OF BULGARIA”. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 16, 2021): 178–182. Accessed April 11, 2025. https://journals.rta.lv/index.php/ETR/article/view/6511.