1. http://en.wikipedia.org/wiki/Virus-Serum-Toxin_Act
2. http://en.wikipedia.org/wiki/Public_Health_Service_Act
3. http://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/CellularandGeneTherapy/UCM169060.txt
4. http://www.carticel.com/
5. http://www.fda.gov/downloads/biologicsbloodvaccines/cellulargenetherapyproducts/approvedproducts/ucm109341.pdf