@article {7518,
	title = {The Type Fox Hills Formation, Cretaceous (Maestrichtian), South Dakota. Part 2. Systematics of the Bivalvia},
	journal = {Peabody Museum of Natural History Bulletin},
	volume = {33},
	year = {1970},
	note = {Pls. 1-42},
	pages = {1-222},
	keywords = {bivalvia, cretaceous, fossils, mesozoic, mollusca, paleontology, phelopteria, pseudoptera, pterioidea, taxonomy, tenuipteria},
	author = {Speden, Ian G.}
}
@article {1578,
	title = {The Type Fox Hills Formation, Cretaceous (Maestrichtian), South Dakota. Part 2. Systematics of the Bivalvia},
	journal = {Peabody Museum of Natural History Bulletin},
	volume = {33},
	year = {1970},
	pages = {1-222},
	keywords = {bivalvia, cretaceous, fossils, mesozoic, mollusca, paleontology, phelopteria, pseudoptera, pterioidea, taxonomy, tenuipteria},
	author = {Speden, Ian G.}
}
