APA-referens (7:e uppl.)

van Hoorn, W., & Keilmann, N. (1997). Birth expectations and their use in fertility forecasting.

Chicago-referens (17:e uppl.)

van Hoorn, Wim, och Nico Keilmann. Birth Expectations and Their Use in Fertility Forecasting. Luxembourg, 1997.

MLA-referens (8:e uppl.)

van Hoorn, Wim, och Nico Keilmann. Birth Expectations and Their Use in Fertility Forecasting. 1997.