	Authors	Year	Title
	Ehiro	2008	Two genera of Popanoceratidae (Permian Ammonoidea) from the South Kitakami, Northeast Japan,with a note on the age of the Takakurayama Formation in the Abukuma Massif. Bulletin Tohoku Univ. Museum 8:1-8
	Sone, Leman & Ehiro	2001	Middle Permian cephalopods from central Peninsular Malaysia:implications for faunal migration through the southern Tethys. Journal of Asian Earth Sciences, 19: 805-814, 11fig.
	Vasicek & Kullmann	1988	Eine Ammonoideen-Fauna vom Sosio-Typ (Guadalupian, Ober-Perm) aus Kurdistan (Irak). Palaeontographica, Abt.A, 204 (1-3): 95-115, fig.1-5, pl.1-2; Stuttgart.
	Vasicek	1988	Upper Permian Ammonoidea from Kurdistan, NE Iraq. In: Wiedmann,J. & Kullmann,J. (eds.), Cephalopods - Present and Past, 577-591, 3 pls., 16 figs., Stuttgart.