Cita APA (7a ed.)
Nygaard, D. F. (1994). World population projections, 2020. International Food Policy Research Institute.
Cita Chicago Style (17a ed.)
Nygaard, David F. World Population Projections, 2020. International Food Policy Research Institute, 1994.
Cita MLA (9a ed.)
Nygaard, David F. World Population Projections, 2020. International Food Policy Research Institute, 1994.
Precaución: Estas citas no son 100% exactas.