erc:
who: Tullis, Edward L.
what: Beryl Resources of the Black Hills of South Dakota
when: 19520300
where: https://digital.library.unt.edu/ark:/67531/metadc38576/
erc-support:
who: University of North Texas Libraries
what: Permanent: Stable Content:
when: 20081203
where: https://digital.library.unt.edu/ark:/67531/