@article{Robine2006,
author = {Robine, J.M. and Caselli, G. and Rasulo, D. and Cournil, A.},
title= {Differentials in the femininity ratio among centenarians: Variations between Northern and Southern Italy from 1870},
year = {2006},
doi = {10.1080/00324720500466000},
journal = {Population Studies},
volume = {60},
number = {1},
pages = {99--113},
}