R. Armitage
- Comparison of ballast index tests for railway trackbeds. In: Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, v. 157, n. 3 (Juli 2004). (2004):
- Laboratory simulation of train loading and tamping on ballast. In: Proceedings of the Institution of Civil Engineers - Transport, v. 158, n. 2 (Mai 2005). (2005):