World Health Organization Kobe Center. (1999). Ageing and health: A global challenge for the 21st century. World Health organization.
Chicago Style aipamenaWorld Health Organization Kobe Center. Ageing and Health: A Global Challenge for the 21st Century. Belgium: World Health organization, 1999.
MLA aipamenaWorld Health Organization Kobe Center. Ageing and Health: A Global Challenge for the 21st Century. World Health organization, 1999.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.