@Inproceedings{ tovariance,
	title = "The principle of general tovariance",
	booktitle = "Proc. XVI International Fall Workshop on Geometry and Physics (Lisbon, 2007)",
	author = "Chris Heunen and Klaas Landsman and Bas Spitters",
	editor = "R. Loja Fernandes and R. Pickens",
	year = "2008",
	url = "http://philsci-archive.pitt.edu/archive/00003931",
	publisher = "American Physical Society"
}