@Unpublished{K-theory/0944,
  author = 	 {{Benjamin Antieau}},
  title = 	 {{Cohomological Obstruction Theory for Brauer Classes and the Period-Index Problem}},
  note = 	 {{Preprint, April 28, 2010, K-theory Preprint Archives, http://www.math.uiuc.edu/K-theory/0944/}}}
}