@Article{	  KufleitnerWa2018tocs,
  year		= "2018",
  publisher	= "Springer",
  author	= "Kufleitner, Manfred and Walter, Tobias",
  title		= "Level two of the quantifier alternation hierarchy over
		  infinite words",
  pages		= "467--480",
  volume	= "62",
  issue		= "3",
  journal	= "Theory of Computing Systems"
}