WHO(world health organization). (2005). Healthy ageing: Practical pointers on keeping well. WHO.
استشهاد بنمط شيكاغوWHO(world health organization). Healthy Ageing: Practical Pointers on Keeping Well. Geneva: WHO, 2005.
MLA استشهادWHO(world health organization). Healthy Ageing: Practical Pointers on Keeping Well. WHO, 2005.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.