Dyfyniad APA

Smith, K., & Petley, D. N. (2009). Environmental Hazards: Assessing risk and reducing disaster (5th ed.). Routledge.

Dyfyniad Arddull Chicago

Smith, Keith, and David N. Petley. Environmental Hazards: Assessing Risk and Reducing Disaster. 5th ed. London: Routledge, 2009.

Dyfyniad MLA

Smith, Keith, and David N. Petley. Environmental Hazards: Assessing Risk and Reducing Disaster. 5th ed. Routledge, 2009.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.