Gaya APA

Enger, E, D., Smith, B, F. (2002). Environmental science (Eighth edition). : The McGraw-Hill.New York.

Gaya MLA

Enger, Eldon, D., Smith, Bradley, F. "Environmental science". Eighth edition : The McGraw-Hill.New York, 2002. Skripsi, Tesis, Disertasi.