1. Yamafuji, K., Miyakawa, Y., & Kawamura, T. (1985). Synchronous steering control of a parallel bicycle. Transactions of the Japan Society of Mechanical Engineers, 55(513), 1229–1234.
2. Grasser, F., Arrigo, A. D., Colombi, S., et al. (2002). JOE: A mobile inverted pendulum. IEEE Transactions on Industrial Electronics, 49(1), 107–114.
3. Salerno, A., & Angeles, J. (2007). A new family of two-wheeled mobile robots: Modeling and controlability. IEEE Trans on Robotics, 23(1), 169–173.
4. Arling, A. W., Chang, S. T., & Field, J. D., et al. (2006). Personal transporter. United States Design Patent. US D528468S, 19 Sep, 2006.
5. Ghani, N., Naim, F., & Yon, T. (2011). Two wheels balancing robot with line following capability. World Academy of Science, Engineering and Technology, 55(7), 1401–1405.