Studying the mechanical properties of (Cu1-xAgx)7GeS5I mixed crystals by using the micro-indentation method - V. V. Bilanych; A. V. Bendak; K. V. Skubenych; A. I. Pogodin; V. S. Bilanych; I. P. Studenyak (Semiconductor Physics, Quantum Electronics and Optoelectronics, 2018)