title: Fermi surface in YBa2Cu3O6.9: Evidence from angle-resolved photoemission spectroscopy and positron two-dimensional angular correlation of annihilation radiation.
authors.initials: JC
authors.lastname: Campuzano
authors.initials: LC
authors.lastname: Smedskjaer
authors.initials: R
authors.lastname: Benedek
authors.initials: G
authors.lastname: Jennings
authors.initials: A
authors.lastname: Bansil