1. 1) T. D. Rossing, The Science of Sound (Addison-Wesley, 1990), pp. 280–284.
2. Modal analysis of a Korean bell
3. Increasing the lifetime of warble-suppressed bells
4. 4) T. Miura, A. Yarai and T. Nakanishi, “Acoustical analysis for the influences of komazume of the temple bell by Finite Element Method,” Proc. Spring Meet. Acoust. Soc. Jpn., pp. 569–570 (2000).
5. 5) Chronological Scientific Tables (National Astronomical Observatory, Maruzen., Tokyo, 1998), pp. 443, 451.