H.-P. Cao, T.-D. Nguyen, and H.-D. Tran, “A Research on the Effect of Velocity and Road Type on the Ride Smoothness of 16-Seat Passenger Buses Using a Mechanical Suspension System”, Eng. Technol. Appl. Sci. Res., vol. 16, no. 1, pp. 32485–32491, Feb. 2026.