Author:

Schopf,J.M.

Year:

1938

Title:

Spores from the Herrin (No. 6) Coal Bed in Illinois.

Reference:

Schopf,J.M. (1938) Spores from the Herrin (No. 6) Coal Bed in Illinois. Illinois State Geological Survey, Report of Investigations # 50 P. 1- 73

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