Detailed study on optical properties of Li2B4O7 for down-conversion to millimeter waves / D. M. Ezhov, N. A. Nikolaev, A. A. Mamrashev, Y. M. Andreev // Proceedings of SPIE. 2021. Vol. 12086 : XV International Conference on Pulsed Lasers and Laser Applications, 2021, Tomsk, Russian Federation. P. 1208626-1-1208626-6. URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/koha:000902704