Enger, E. D., & Smith, B. F. (2000). Environmental Science: A Study of Interrelationships (7th ed.). McGraw-Hill.
Cita Chicago (17th ed.)Enger, Eldon D., i Bradley F. Smith. Environmental Science: A Study of Interrelationships. 7th ed. Boston: McGraw-Hill, 2000.
Cita MLA (9th ed.)Enger, Eldon D., i Bradley F. Smith. Environmental Science: A Study of Interrelationships. 7th ed. McGraw-Hill, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.