1. World Health Organization Data and Statistics http://www.who.int/topics/ageing/en/
2. Turkish Statistical Institute Population by Years, Age Group and Gender http://www.tuik.gov.tr/UstMenu.do?metod=temelist
3. Trends of elderly population in the world and Turkey: problems and recommendations [Dünya'da ve Türkiye'de yaşlı nüfus eğilimi, sorunları ve iyileştirme önerileri];Akgun;Turk J Geriatr,2004
4. Assessment and measurement of pain in older adults;Herr;Clin Geriatr Med,2001