Παραπομπή σε μορφή APA (7η εκδ.)

Kopp, R. J., & Smith, V. K. (1993). Valuing natural assets: The economics of natural resource damage assessment. Resources for the Future.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Kopp, Raymond J., και V. Kerry Smith. Valuing Natural Assets: The Economics of Natural Resource Damage Assessment. Washington: Resources for the Future, 1993.

Παραπομπή σε μορφή MLA (9th εκδ.)

Kopp, Raymond J., και V. Kerry Smith. Valuing Natural Assets: The Economics of Natural Resource Damage Assessment. Resources for the Future, 1993.