Environmental science : a study of interrelationships. Enger, Eldon D. Smith, Bradley Fraser. Environmental sciences. 363 HIL 2004 A079 Or. Boston : McGraw-Hill Higher Education, c2004. c2004. Text 1 v. (various pagings) : http://www.loc.gov/catdir/toc/fy037/2002075341.html http://www.loc.gov/catdir/enhancements/fy0643/2002075341-d.html