Gaya APA

Cunningham, M, A., Cunningham, W, P. (2008). Principles of environmental science : inquiry and applications (4th ed.). Boston, Massachusetts: McGraw Hill Higher Education.

Gaya MLA

Cunningham, Mary, Ann., Cunningham, William, P.. "Principles of environmental science : inquiry and applications". 4th ed. Boston, Massachusetts: McGraw Hill Higher Education, 2008. Text.