erc:
who: Duffy, J. R.
what: [Letter from colonel J. R. Duffy to the U.S. Army Primary Helicopter School, September 26, 1966]
when: 19660926
where: https://texashistory.unt.edu/ark:/67531/metapth823308/
erc-support:
who: University of North Texas Libraries
what: Permanent: Stable Content:
when: 20081203
where: https://texashistory.unt.edu/ark:/67531/