Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (9a ed.)

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