Cita APA (7a ed.)
Callahan, D. Ethics and Population Limitation. Population Council.
Cita estilo Chicago (17a ed.)
Callahan, Daniel. Ethics and Population Limitation. Nueva York, EUA: Population Council.
Cita MLA (9a ed.)
Callahan, Daniel. Ethics and Population Limitation. Population Council.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.