WHO(world health organization). (2005). Healthy ageing: Practical pointers on keeping well. WHO.
Chicago Style aipamenaWHO(world health organization). Healthy Ageing: Practical Pointers on Keeping Well. Geneva: WHO, 2005.
MLA aipamenaWHO(world health organization). Healthy Ageing: Practical Pointers on Keeping Well. WHO, 2005.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.