Prospective visible laser active media based on disordered fluorite-type structure crystals / The European Physical Journal Conferences (IWQO-2019) 220, 03024 (2019) 

Oleg Morozov, Sergey Kuznetsov, Vasiliy Konyushkin, and Andrey Nakladov, Alexey Nizamitdinov, Pavel Fedorov and Vadim Semashko. Prospective visible laser active media based on disordered fluorite-type structure crystals / The European Physical Journal Conferences (IWQO-2019) 220, 03024 (2019)  

https://doi.org/10.1051/epjconf/201922003024