1. Advanced Rail Geotechnology-Ballasted Track;Indraratna,2011
2. Railway Geotechnics;Dingqing,2015
3. E.T. Selig, Ernest Theodore, J.M. Waters. Track geotechnology and substructure management. Thomas Telford, (1994).
4. F. Feldman, D. Nissen. Alternative testing method for the measurement of ballast fouling: percentage void contamination. CORE 2002: Cost efficient railways through engineering (2002): 101.
5. D. Ionescu, Ballast degradation and measurement of ballast fouling. Seventh Railway Engineering Conference, Common wealth Institute, London, (2004).