Viessman, W., & Hammer, M. J. (1998). Water supply and pollution control (6th.ed.). Addison-Wesley.
Dyfyniad Arddull ChicagoViessman, Warren, and Mark J. Hammer. Water Supply and Pollution Control. 6th.ed. Menlo Park: Addison-Wesley, 1998.
Dyfyniad MLAViessman, Warren, and Mark J. Hammer. Water Supply and Pollution Control. 6th.ed. Addison-Wesley, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.