@inproceedings{PODS-1993-Wong,
	author        = "Limsoon Wong",
	booktitle     = "{Proceedings of the 12th Symposium on Principles of Database Systems}",
	cdrom         = "['journals/anthology/cd1-3:PODS93/P026.PDF', 'journals/anthology/dvd1:text/1-3/PODS93/P026.PDF']",
	doi           = "10.1145/153850.153853",
	isbn          = "0-89791-593-3",
	pages         = "26--36",
	publisher     = "{ACM Press}",
	title         = "{Normal Forms and Conservative Properties for Query Languages over Collection Types}",
	year          = 1993,
}