Pennsylvanian tree fern compressions Caulopteris, Megaphyton, and Artisophyton gen. nov. in Illinois /
Hermann W. Pfefferkorn.
APA Citation
Pfefferkorn, H. W., Illinois State Geological Survey., Illinois. Dept. of Registration and Education. (1976). Pennsylvanian tree fern compressions Caulopteris, Megaphyton, and Artisophyton gen. nov. in Illinois. Urbana: Illinois State Geological Survey.
MLA Citation
Pfefferkorn, Hermann W, Illinois State Geological Survey, and Illinois. Dept. of Registration and Education. Pennsylvanian Tree Fern Compressions Caulopteris, Megaphyton, And Artisophyton Gen. Nov. In Illinois. Urbana: Illinois State Geological Survey, 1976.
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