PETROVA, Desislava; VLAHOVA, Beata; LENGEROV, Angel; ZLATEVA-PETKOVA, Tsanka. STUDY OF THE STATE OF INNOVATION DEVELOPMENT AND OBSOLESCENCE IN THE REPUBLIC OF BULGARIA OF COMPANIES FROM THE MECHANICAL ENGINEERING SECTOR. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, Rezekne, Latvia, v. 1, p. 187–194, 2023. DOI: 10.17770/etr2023vol1.7239. Disponível em: https://journals.rta.lv/index.php/ETR/article/view/7239.. Acesso em: 15 dec. 2024.