Spengler, J. J. (1972). Population economics: Selected essays of Joseph John Spengler. Duke University Press.
Čikaški stil citiranja (17. izdanje)Spengler, Joseph John. Population Economics: Selected Essays of Joseph John Spengler. Durham, North Carolina: Duke University Press, 1972.
MLA način citiranja (9. izdanje)Spengler, Joseph John. Population Economics: Selected Essays of Joseph John Spengler. Duke University Press, 1972.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.