Παραπομπή APA

Christian, S. (1998). What makes the grand canyon grand?: The world's most awe-insping natural wonders. J. Wiley.

Παραπομπή Chicago Style

Christian, Spencer. What Makes the Grand Canyon Grand?: The World's Most Awe-insping Natural Wonders. J. Wiley, 1998.

Παραπομπή MLA

Christian, Spencer. What Makes the Grand Canyon Grand?: The World's Most Awe-insping Natural Wonders. J. Wiley, 1998.

Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.