@inproceedings{BX-2014-JohnsonR,
	author        = "Michael Johnson and Robert D. Rosebrugh",
	booktitle     = "{Proceedings of the Third International Workshop on Bidirectional Transformations}",
	ee            = "http://ceur-ws.org/Vol-1133/paper-18.pdf",
	pages         = "112--118",
	title         = "{Spans of lenses}",
	year          = 2014,
}