Chukova, O., and S. Nedilko. “Structure of Centers of Matrix Emission of the Undoped and RE-Doped Scheelite-Type Lead Tungstate Crystals”. Ukrainian Journal of Physics 64, no. 9 (October 11, 2019): 837. Accessed May 7, 2024. https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2019449.