Lazov, Lyubomir, Nikolay Todorov Dolchinkov, Jordan Shterev Ivanov, Madlen Nikolaeva Peneva, and Denitsa Angelova Bojhanova. 2019. “STUDY OF LASER CUTTING AND MARKING ON THE FILT WITH THE HELP OF A CO2-LASER”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (June): 143-47. https://doi.org/10.17770/etr2019vol3.4202.