1. Colby SO, Ortman JM. Projections of the size and composition of the U.S. population: 2014 to 2060. Population estimates and projections. Washington, DC: U.S. Census Bureau 2014.
2. United NationsDepartment of Economic and Social Affairs, Population Division. World population prospects: the 2010 revision, volume I: comprehensive tables. 2011. ST/ESA/SER.A/313.
3. Blue journal conference. Aging and susceptibility to lung disease;Thannickal;Am J Respir Crit Care Med,2015
4. Chronic obstructive pulmonary disease diagnosis and management in older adults;Gooneratne;J Am Geriatr Soc,2010
5. Multimorbidity—older adults need health care that can count past one;Banerjee;Lancet,2015