@Unpublished{Algebraic-Number-Theory/0292,
  author = 	 {{Catherine H. O'Neil}},
  title = 	 {{The Period-Index Obstruction}},
  note = 	 {{Preprint, November 2, 2002, Algebraic Number Theory Preprint Archives, http://www.math.uiuc.edu/Algebraic-Number-Theory/0292/}}}
}