1. (1) Saito, K. Yamauchi, N., Yoshimura, T., Yamanaka, T., Yasuhara, H., Uemura, M. and Sato, Y., Helicopter 2nd ed., (1993), pp.115-124, Japan Aeronautical Engineers' Association.
2. (2) Kato, K. and Imanaga, I., Introduction to Helicopter, (1985), pp.197-203, University of Tokyo Press.
3. (3) Genta, G., Dynamics of Rotating Systems, (2005), pp.465-515, Springer.