Nebel, B. J. (1998). Environmental sciencethe way the world works. Prentice-Hall.
Dyfyniad Arddull ChicagoNebel, Bernard J. Environmental Sciencethe Way the World Works. Prentice-Hall, 1998.
Dyfyniad MLANebel, Bernard J. Environmental Sciencethe Way the World Works. Prentice-Hall, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.