@inproceedings{VLDB-1975-Tsubaki,
	author        = "Masaaki Tsubaki",
	booktitle     = "{Proceedings of the First International Conference on Very Large Data Bases}",
	cdrom         = "VLDB75/P538.PDF",
	doi           = "10.1145/1282480.1282541",
	pages         = "538--539",
	publisher     = "{ACM}",
	title         = "{Multi-Level Data Model in DPLS — Database, Dynamic Program Control & Open-Ended Pol Support}",
	year          = 1975,
}