[1] [CITE[MARC 21 Format for Authority Data: Appendix A: Control Subfields (Network Development and MARC Standards Office, Library of Congress)]], [[Library of Congress Network Development and MARC Standards Office]], [TIME[2021-06-03T22:08:58.000Z]], [TIME[2022-12-11T13:01:41.678Z]] <https://www.loc.gov/marc/authority/ecadcntf.html>