THE CHANGE OF CONTRAST IS INVESTIGATION OF 75 STEEL SAMPLES LASER MARKED WITH DIFFERENT MODES. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference, [S. l.], v. 3, p. 334–338, 2024. DOI: 10.17770/etr2023vol3.7264. Disponível em: https://archive-journals.rtu.lv/etr/article/view/4636.. Acesso em: 11 mar. 2026.