FIETZ, W.; WASSILEW С. A.; LUDWIG, H. A.; OBST В.; DIETRICH, M. R.; WUHL, H. Structural Changes of High-T_c Superconductors under Pressures up to 29 GPa and at Temperatures Between 15 and 300 K. Fiz. Nizk. Temp. 1990, 16, 615-617.