Young, K. (1951). Foraminifera and Stratigraphy of the Frontier Formation (Upper Cretaceous), Southern Montana. Journal of Paleontology. Vol. 25, No. 1 (Jan., 1951), pp. 35-68.
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Young, K.
1951
Foraminifera and Stratigraphy of the Frontier Formation (Upper Cretaceous), Southern Montana