1. US Government Accountability Office (GAO): Emergency preparedness: improved planning and coordination necessary for development of integrated public alert and warning system. 2009, GAO-09-834.
http://www.gao.gov/products/GAO-09-834
. Accessed 10 September 2014
2. A Calderon: Land mobile radio: following a realistic path toward broadband for PPDR services. IEEE Vehicular Technol. Mag 2013, 8(2):37-45.
3. Analysis Mason: Report for the TETRA Association: public safety mobile broadband and spectrum needs, vol 16395-94. Analysis Mason, London; 2010.
4. R Ferrus: LTE: the technology driver for future public safety communications. IEEE Commun. Mag 2013, 51(10):154-161.
5. AG Fragkiadakis: Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks. EURASIP J. Wireless Commun. Network 2011, 2011(13):1-16. doi:10.1186/1687-1499-2011-13