skos:altLabel | - Koppers Chemical
- Koppers Chemicals
- Koppers Co.
- Koppers Co., Inc.
- Koppers Co., Inc. (Charleston Plant)
- Koppers Co., Inc. (Florence Plant)
- Koppers Company
- Koppers Company, Inc
- Koppers Holdings Inc.
- Koppers Holdings, Inc.
- Koppers Inc.
- Koppers International
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