Harper, C. L. (2008). Environment and society: Human perspectives on environmental issues (4th ed.). Upper Saddle River, N.J.: Pearson/Prentice Hall.
Dyfyniad Arddull ChicagoHarper, Charles L. Environment and Society: Human Perspectives On Environmental Issues. 4th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2008.
Dyfyniad MLAHarper, Charles L. Environment and Society: Human Perspectives On Environmental Issues. 4th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2008.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.