@inproceedings{SIGMOD-1989-GyssensPG,
	author        = "Marc Gyssens and Jan Paredaens and Dirk Van Gucht",
	booktitle     = "{Proceedings of the 19th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD89/P263.PDF",
	doi           = "10.1145/67544.66951",
	pages         = "263--272",
	title         = "{A Grammar-Based Approach Towards Unifying Hierarchical Data Models}",
	year          = 1989,
}