Yamaguchi, T. , Kurosawa, Y. , Maruyama, S. , Tobita, K. , Hirano, Y. , Yokouchi, K. , Kihara, K. , Sunaga, T.. "Nonlinear and Chaotic Motions for a Shock Absorbing Structure Supported by Nonlinear Springs with Hysteresis Using Fast FEA". World Academy of Science, Engineering and Technology, Open Science Index 79, International Journal of Mechanical and Mechatronics Engineering, (2013), 7(7), 1562 - 1573.