Author:

Ravn,R.L.

Year:

1986

Title:

Palynostratigraphy of the Lower and Middle Pennsylvanian Coals of Iowa

Reference:

Ravn,R.L. (1986) Palynostratigraphy of the Lower and Middle Pennsylvanian Coals of Iowa Iowa Geological Survey,Technical Paper # 7 P. 1- 244

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