erc: who: Biryukov, V. M. what: 50x50 GeV Muon Collider Beam Collimation when: 19990414 where: https://digital.library.unt.edu/ark:/67531/metadc691943/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/