Phase matching in RT KTP crystal for down-conversion into the THz range / J.-G. Huang, Z.-M. Huang, N. A. Nikolaev [et al.] // Laser physics letters. 2018. Vol. 15, № 7. P. 075401 (1-4). URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000646053