Hill, M. (2004). understanding environmental pollution (2nd.). CUP.
Cita Chicago (17th ed.)Hill, Marquita. Understanding Environmental Pollution. 2nd. Cambridge: CUP, 2004.
Cita MLA (9th ed.)Hill, Marquita. Understanding Environmental Pollution. 2nd. CUP, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.