@inproceedings{SIGFIDET-1970-BracchiFS,
	author        = "Giampio Bracchi and Domenico Ferrari and Marco Somalvico",
	booktitle     = "{Record of the First ACM SIGFIDET Workshop on Data Description and Access}",
	cdrom         = "SIGFIDET70/P246.pdf",
	pages         = "246--275",
	publisher     = "{ACM}",
	title         = "{A Multilevel Data Structure for Complex Hierarchies of Interrelated Data}",
	year          = 1970,
}