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Ruan & Zhou |
1987 |
Carboniferous cephalopods in Ningxia Hui Autonomous Region. [In Chinese, with Engl. summary].
Namurian Strata and Fossils of Ningxia, China: 55-177, 78 text-figs., 15 pls., Nanjing.
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Yang |
1986 |
Late Early Carboniferous ammonoids from Chenmazijing of Zhongning, Ningxia.
Acta Paleontologica Sinica, 25 (3): 260-271, fig.1-21, pl.1-2; Beijing.
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