@inproceedings{CSL-1997-Schweikardt,
	author        = "Nicole Schweikardt",
	booktitle     = "{Selected Papers of the 11th International Workshop on Computer Science Logic / Annual Conference of the EACSL}",
	doi           = "10.1007/BFb0028030",
	isbn          = "3-540-64570-5",
	pages         = "441--460",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{The Monadic Quantifier Alternation Hierarchy over Grids and Pictures}",
	volume        = 1414,
	year          = 1997,
}