Istrate, Emilia; Nadeau, Carey Anne. Global MetroMonitor. Washington, DC: The Brookings Institution. November 2012 [23 December 2013]. (原始内容存档于2013年6月4日).
Haywood, Russ. Britain's national railway network: fit for purpose in the 21st century?. Journal of Transport Geography (Elsevier). 2007, 15 (3): 198–216. doi:10.1016/j.jtrangeo.2006.02.015.
Istrate, Emilia; Nadeau, Carey Anne. Global MetroMonitor. Washington, DC: The Brookings Institution. November 2012 [23 December 2013]. (原始内容存档于2013年6月4日).