Fried LP, Tangen CM, Walston J, Newman AB, Hirsch C, Gottdiener J, Seeman T, Tracy R, Kop WJ, Burke G, et al. Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001  ;56(3):M146-56.

Kop WJ, Kuhl EA, Barasch E, Jenny NS, Gottlieb SS, Gottdiener JS. Association between depressive symptoms and fibrosis markers: the Cardiovascular Health Study. Brain Behav Immun. 2010  ;24(2):229-35.

Dalrymple LS, Katz R, Rifkin DE, Siscovick D, Newman AB, Fried LF, Sarnak MJ, Odden MC, Shlipak MG. Kidney function and prevalent and incident frailty. Clin J Am Soc Nephrol. 2013  ;8(12):2091-9.