Gaya APA

Schor, H, J., Gray, D, H. (2007). Landforming: an Environmental Approch to Hillside Development, Mine Reclamation and Watershed Restoration . New Jersey: John Wiley and Sons, Inc..

Gaya MLA

Schor, Horst, J.., Gray, Donald, H. "Landforming: an Environmental Approch to Hillside Development, Mine Reclamation and Watershed Restoration". New Jersey: John Wiley and Sons, Inc., 2007. Text.