Comments on the paper Growth and Characterization of Pure and Thiourea-Doped L-Alanine Single Crystals for NLO Devices

we show that the pure and thiourea-doped glycyl-L-alanine hydrochloride (GLAH and TU-GLAH) crystals claimed to have been grown by the authors of the title paper (Journal of Russian Laser Research, 34, 346-350 (2013)) are dubious crystals.