O. M. Pop, V. T. Maslyuk, V. I. Roman, I. H. Megela, I. V. Pylypchynets, E. V. Oleinikov, and O. O. Papp, Radiation coloring of undoped lithium fluoride crystals , Low Temp. Phys. 51, 310–315, (2025) [Fiz. Nyzk. Temp. 51, 343–348, (2025)] DOI: https://doi.org/10.1063/10.0035813.