Viesssman, W., & Welty, C. (1985). Water management: Technology and institutions. Harper.
Dyfyniad Arddull ChicagoViesssman, Warren, and Clare Welty. Water Management: Technology and Institutions. Cambrdge: Harper, 1985.
Dyfyniad MLAViesssman, Warren, and Clare Welty. Water Management: Technology and Institutions. Harper, 1985.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.