Citazione Stile APA (7a Edizione)

Keyfitz, N. (1990). World population growth and aging: Demographic trends in the late twentieth century. University of Chicago Press.

Citazione stile Chigago Style (17a edizione)

Keyfitz, Nathan. World Population Growth and Aging: Demographic Trends in the Late Twentieth Century. Chicago: University of Chicago Press, 1990.

Citatione MLA (9a ed.)

Keyfitz, Nathan. World Population Growth and Aging: Demographic Trends in the Late Twentieth Century. University of Chicago Press, 1990.