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
Liang
1982
Some Early Permian ammonoids from Jilin and Nei Monggol.
