Gaya APA

Cunningham, W, P., Cunningham, M, A. (2002). Principles of Environmental Science : Inquiry and Applications (Ed. 1). Boston: Mcgraw Hill, Inc.

Gaya MLA

Cunningham, William, P.., Cunningham, Mary, Ann. "Principles of Environmental Science : Inquiry and Applications". Ed. 1 Boston: Mcgraw Hill, Inc, 2002. Text.