Cita APA (7th ed.)

Keyfitz, N., & Flieger, W. (1971). Population: Facts and methods of demography. W. H. Freeman.

Cita Chicago (17th ed.)

Keyfitz, Nathan, i Wilhelm Flieger. Population: Facts and Methods of Demography. San Francisco: W. H. Freeman, 1971.

Cita MLA (8th ed.)

Keyfitz, Nathan, i Wilhelm Flieger. Population: Facts and Methods of Demography. W. H. Freeman, 1971.