@inproceedings{ICFP-2009-Voigtlander,
	author        = "Janis Voigtländer",
	booktitle     = "{Proceedings of the 14th International Conference on Functional Programming}",
	doi           = "10.1145/1596550.1596577",
	editor        = "Graham Hutton and Andrew P. Tolmach",
	isbn          = "978-1-60558-332-7",
	pages         = "173--184",
	publisher     = "{ACM}",
	title         = "{Free theorems involving type constructor classes: functional pearl}",
	year          = 2009,
}