@inproceedings{PPDP-2000-PowerR,
	author        = "John Power and Edmund Robinson",
	booktitle     = "{Proceedings of the Second International Conference on Principles and Practice of Declarative Programming}",
	doi           = "10.1145/351268.351271",
	pages         = "15--23",
	title         = "{Logical relations, data abstraction, and structured fibrations}",
	year          = 2000,
}