Wrigley, E. A. (2004). Poverty, progress, and population. Cambridge University Press.
Dyfyniad Arddull ChicagoWrigley, E. A. Poverty, Progress, and Population. Cambridge: Cambridge University Press, 2004.
Dyfyniad MLAWrigley, E. A. Poverty, Progress, and Population. Cambridge University Press, 2004.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.