Helsop, A. (1999). Ageing and Development.
Cita Chicago (17th ed.)Helsop, Amanda. Ageing and Development. 1999.
Cita MLA (8th ed.)Helsop, Amanda. Ageing and Development. 1999.
Atenció: Aquestes cites poden no estar 100% correctes.
Cita APA (7th ed.)