Khosroabadi, H., Kobayashi, J., Tanaka, K., Miyasaka, S., Tajima, S., Uchiyama, H., & Baron, A. "Softening of high energy phonons by insulator-superconductor transition in Ba1-xKxBiO3 system", Iranian Journal of Physics Research, 10, 2, 2019, 117-120.