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3. 3. Cruz Roja Mexicana [homepage on the Internet]. Distrito Federal: Cruz Roja Mexicana I.A.P.; c2007. [cited 2008 Feb 14]. Available from: http://www.cruzrojamexicana.org.mx
4. 4. National Blood Service [homepage on the Internet]. London: National Blood Service; c2002. [cited 2008 Feb 14]. Available from: http://www.blood.co.uk
5. 5. Irish Blood Transfusion Service [homepage on the Internet]. Dublin: Irish Blood Transfusion Service; c2005. [cited 2008 Feb 14]. Available from: http://www.ibts.ie