1.
|
|
2.
|
|
3.
|
Urbana : Illinois State Geological Survey, 1943.
|
4.
|
Urbana : Illinois State Geological Survey, 1935.
|
5.
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Urbana, State Geological Survey, 1956.
|
6.
|
|
7.
|
|
8.
|
|
9.
|
Urbana : Illinois State Geological Survey, c1935.
|
10.
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Urbana : Illinois State Geological Survey, 1957.
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