Παραπομπή σε μορφή APA (7η εκδ.)

Simpson, R. D. (1999). Productivity in natural resource industries: Improvement through innovation. Resources for the Future.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Simpson, Ralph David. Productivity in Natural Resource Industries: Improvement Through Innovation. Washington, D.C.: Resources for the Future, 1999.

Παραπομπή σε μορφή MLA (8th εκδ.)

Simpson, Ralph David. Productivity in Natural Resource Industries: Improvement Through Innovation. Resources for the Future, 1999.