1. In Deaths at Rail Crossings, Missing Evidence and Silence;Bogdanich;New York Times,2004
2. U.S. Government Accountability Office (GAO) 2004 Rail Security: Some Actions Taken to Enhance Passenger and Freight Rail Security, but Significant Challenges Remain Government Printing Office http://www.gao.gov/new.items/d04598t.pdf
3. U.S. Government Accountability Office (GAO) 2005 Passenger Rail Security: Enhanced Federal Leadership Needed to Prioritize and Guide Security Efforts Government Printing Office http://www.gao.gov/new.items/d06181t.pdf
4. U.S. Government Accountability Office (GAO) 2006 Freight Railroads: Preliminary Observations on Rates, Competition, and Capacity Issues Government Printing Office http://www.gao.gov/new.items/d06898t.pdf