|
Gordon |
1965 |
Carboniferous Cephalopods of Arkansas.
Professional Papers, U.S. Geological Survey, 460: 1-322, fig.1-96, pl.1-32; Washington. [imprint 1964].
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|
Mapes & Furnish |
1981 |
The Pennsylvanian ammonoid family Welleritidae.
Journal of Paleontology, 55 (2): 317-330, fig.1-8, pl.1-2; Tulsa, Okla.
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