Dyfyniad APA

 Worrell, W. A. (2011).  Solid waste engineering, si.  South-Western, Cengage Learning.

Dyfyniad Arddull Chicago

 Worrell, William A.  Solid Waste Engineering, Si.  South-Western, Cengage Learning, 2011.

Dyfyniad MLA

 Worrell, William A.  Solid Waste Engineering, Si.  South-Western, Cengage Learning, 2011.

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