1. Ballesteros, J.P., 2006. GRAIL project: GNSS introduction in the rail sector. EURNEX-ŽEL 2006. In: 14th International Symposium: Towards the Competitive Rail Systems in Europe, Žilina, Slovakia.
2. Barbu, G., 2007. GALILEO certifies for rail, which safety case? In: CERGAL Conference – Certification of GNSS Systems & Services, Braunschweig, Germany.
3. Barbu, G., 2008. GNSS/GALILEO certification for rail safety applications, Railway requirements and the strategic position of UIC. The 8th World Congress on Railways Research – WCRR, Seoul, Korea.
4. Bustamante, J., De Miguel, S., 2003. GADEROS – a technological approach to GNSS-aided railway traffic monitoring for conventional and low-density traffic lines – interoperability of GNSS-based location with ERTMS/ETCS on-board. Intelligent Transport Systems and Services, Madrid, Spain.
5. Butzmuehlen, C., 2007. GALCERT, Support to the certification of Galileo. In: CERGAL Conference – Certification of GNSS Systems & Services, Braunschweig, Germany.