INDUSTRY 4.0 – ADVANTAGES ANDCHALLENGES IN THE REPUBLIC OF BULGARIA. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference, [S. l.], v. 1, p. 178–182, 2021. DOI: 10.17770/etr2021vol1.6511. Disponível em: https://archive-journals.rtu.lv/etr/article/view/4422.. Acesso em: 11 mar. 2026.