1. European Union EU Directive 2004/23/EC, Article 8, para 4 http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32004L0023:EN:HTML
2. US Food and Drug Administration Code of Federal Regulations, 21CFR606.160 (d) http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=606.160
3. Coding and traceability: cells and tissues in North America;Brubaker;Cell Tissue Bank,2010
4. Transmission of hepatitis C virus through transplanted organs and tissue - Kentucky and Massachusetts, 2011;Marvin;MMWR Morb Mortal Wkly Rep,2011
5. ISBT Consistent Coding Systems http://www.who.int/transplantation/tra_isbt/en/