1. CFR 50, Subpart D. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=50&showFR=1&subpartNode=21:1.0.1.1.19.4 . Accessed 3 Jan 2011
2. CFR 50.3(k). http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=50.3 . Accessed 3 Jan 2011
3. CFR 50.3(n). http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=50.3 . Accessed 3 Jan 2011
4. CFR 50.3(o). http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=50.3 . Accessed 3 Jan 2011
5. CFR 50.24. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=50.24 . Accessed 3 Jan 2011