Smith, Peri; Kyriakidis, Miltos; Majumdar, Arnab; Ochieng, Washington Y (2012). "Impact of European Railway Traffic Management System on Human Performance in Railway Operations European Findings". SSRN Working Paper Series. doi:10.2139/ssrn.2506609. ISSN1556-5068.
London, Main campus address: Imperial College; Campus, South Kensington. "Positioning, navigation and timing". Imperial News. Imperial College London. Retrieved 2021-11-07.
Smith, Peri; Kyriakidis, Miltos; Majumdar, Arnab; Ochieng, Washington Y (2012). "Impact of European Railway Traffic Management System on Human Performance in Railway Operations European Findings". SSRN Working Paper Series. doi:10.2139/ssrn.2506609. ISSN1556-5068.