1. (1) Kotera, T. and Kawai, R., Vibrations of String with Time-Varying Length (2nd Report, Free Vibrations Induced by Initial Displacements) (in Japanese), Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 54, No. 497 (1988), pp. 9-15.
2. (2) Hashimoto, Y., Free Vibration of String with Time-Varying Length (in Japanese), Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 57, No. 539 (1991), pp. 2167-2169.
3. (3) Kotera, T., Vibration of String with Time-Varying Length (on the Exact Solution) (in Japanese), Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 60, No. 571 (1994), pp. 765-768.
4. (4) Hashimoto, Y., Finite Element Dynamic Response Analysis of a String with Time-Varying Length (in Japanese), Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 70, No. 693 (2004), pp. 1263-1267.
5. (5) Yamamoto, T. et al., Vibration of a String with Time-Varying Length (in Japanese), Transactions of the Japan Society of Mechanical Engineers, Vol. 44, No. 380 (1978), pp. 1175-1182.