@article{McGue2001,
author = {McGue, M. and Christensen, K.},
title= {The heritability of cognitive functioning in very old adults: Evidence from Danish twins aged 75 years and older},
year = {2001},
doi = {10.1037/0882-7974.16.2.272},
journal = {Psychology and Aging},
volume = {16},
number = {2},
pages = {272--280},
}