APA (7e ed.) Bronvermelding

Spengler, J. J. (1975). Zero population growth: Implications. Carolina Population Center, University of North Carolina at Chapel Hill.

Chicago (17e ed.) Bronvermelding

Spengler, Joseph John. Zero Population Growth: Implications. Chapel Hill: Carolina Population Center, University of North Carolina at Chapel Hill, 1975.

MLA (9e ed.) Bronvermelding

Spengler, Joseph John. Zero Population Growth: Implications. Carolina Population Center, University of North Carolina at Chapel Hill, 1975.