Dyfyniad APA

Lutz, W., Vaupel, J. W., & Ahlburg, D. A. (1999). Frontiers of population forecasting. Population Council.

Dyfyniad Arddull Chicago

Lutz, Wolfgang, James W. Vaupel, and Dennis A. Ahlburg. Frontiers of Population Forecasting. New York: Population Council, 1999.

Dyfyniad MLA

Lutz, Wolfgang, et al. Frontiers of Population Forecasting. Population Council, 1999.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.