1] Lybomir Lazov MARKING OF PRODUCTS OF STRUCTURAL STEEL WITH COATINGS" - Contemporary Materials - 2013 - Savremeni materijali , 22.03.2013.
(https://ekonferencije.com/sr/rad/marking-of-products-of-structu/2146)

2] Lybomir Lazov A STUDY OF THE INFLUENCE OF THE NUMBER OF REPETITIONS AND DEFOCUSING ON THE LASER MARKING OF PRODUCTS FROM TOOL STEEL" - Contemporary Materials - 2011 - Савремени материјали, 16.06.2011.
(https://ekonferencije.com/sr/rad/a-study-of-the-influence-of-th/760)

3] Lybomir Lazov OPTIMIZATION OF THE PROCESS OF LASER MARKING OF PRODUCTS FROM TOOL STEEL" - Contemporary Materials - 2011 - Савремени материјали, 16.06.2011.
(https://ekonferencije.com/sr/rad/optimization-of-the-process-of/759)