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From
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To
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Geolocation
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Author - title
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Year
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| details | Allegheny | Pennsylvania | Gray,L.R. Palynology of the Middle Kittanning Coal in Ohio | 1966 | |
| details | Allegheny | Ohio | Gray,L.R. Palynology of four Allegheny Coals, northern Appalachian Coal Field. | 1967 |