Fukuda, Shigekazu; Ogawa, Ryohei; Kondo, Takashi . (2001). Frequency Dependence of Free Radical Formation by Ultrasound in the Presence of Different Rare Gases. Japanese Journal of Applied Physics, 40(Part 1, No. 5B), 3493–3494.
doi:10.1143/JJAP.40.3493
