INTELLIGENT, INNOVATIVE AND SUSTAINABLE INDUSTRY IN BULGARIA – PROSPECTS AND CHALLENGES. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference, [S. l.], v. 1, p. 210–215, 2019. DOI: 10.17770/etr2019vol1.4188. Disponível em: https://archive-journals.rtu.lv/etr/article/view/4210.. Acesso em: 11 mar. 2026.