@inproceedings{STOC-1996-Ogihara,
	author        = "Mitsunori Ogihara",
	booktitle     = "{Proceedings of the 28th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/237814.237834",
	isbn          = "0-89791-785-5",
	pages         = "84--88",
	publisher     = "{ACM}",
	title         = "{The PL Hierarchy Collapses}",
	year          = 1996,
}