21 CFR Part 211 of US describes the 'Current Good Manufacturing Practices (cGMP)' for pharmaceutical industry. This is deemed to be dynamic, so that updated principles can be facilitated for implementation.
" The information on this page is current as of April 1 2019. For the most up-to-date version of CFR Title 21, go to the Electronic Code of Federal Regulations (eCFR)."
This sentence cover active link for CRF which redirect into this site: