Παραπομπή σε μορφή APA (7η εκδ.)

Sellars, R. W. (1997). Preserving nature in the national parks: A history : with a new preface and epilogue. Yale University Press.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Sellars, Richard West. Preserving Nature in the National Parks: A History : With a New Preface and Epilogue. New Haven: Yale University Press, 1997.

Παραπομπή σε μορφή MLA (9th εκδ.)

Sellars, Richard West. Preserving Nature in the National Parks: A History : With a New Preface and Epilogue. Yale University Press, 1997.