1. History of Stability of Railway and Road Vehicles
2. Andrews, H. I. 1986.Railway Traction – the Principles of Mechanical and Electrical Railway Traction, 344Elsevier, Amsterdam. (cf. p. 355)
3. Handbook of Railway Vehicle Dynamics
4. Vuchic, V. R. 1981.Urban Public Transportation – Systems and Technology, 481–487. Englewood Cliffs, NJ: Prentice-Hall, Inc. Section 6.2.2