Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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