	Authors	Year	Title
	Ehiro, Hasegawa & Misaki	2005	Permian ammooids Prostacheoceras and Perrinites from the Kitakami Massif, Northeast Japan. Journal of Paleontology, 79 (6): 1222-1228, 6 fig., Lawrence, KS.
	Ehiro & Misaki	2005	Middle Permian ammonoids from the Kamiyasse-Imo district in the Southern Kitakami Massif, Northeast Japan. Paleontological Research, 9: 1-14, 9 fig.