@article{Scheidegger:2008:TTP,
	author={C. Scheidegger and D. Koop and E. Santos and H. Vo and S. Callahan and J. Freire and C. Silva},
	journal={Concurrency and Computation: Practice and Experience},
	number=5,
	pages={473--483},
	title={Tackling the Provenance Challenge One Layer at a Time},
	volume=20,
	year=2008,
}