1. Sperry Rail Service;Allison;Bull Natl Railway Historical Soc,1968
2. An assessment of Railtrack's methods for managing broken and defective rail;Sawley,2000
3. Ultrasonic testing of materials;Krautkramer,1990
4. Falkenbach G, et al. Improvement in magnetic techniques for rail inspection. US DOT (FRA). Report No. DOT-TSC-1244-1; December 1977.
5. National Transportation Safety Board. Rail accident brief. NTSB/RAB-02/01; March 5, 2002.