Increasing Sibling Relative Risk of Survival to Older and Older Ages and the Importance of Precise Definitions of "Aging," "Life Span," and "Longevity"
J. Gerontol. A Biol. Sci. Med. Sci. (2015)
Paola Sebastiani, Lisa Nussbaum, Stacy L Andersen, Mara J Black, Thomas T Perls