@article{T.V.2007,
author = {T.V., Pollet and Nettle, D. and Nelissen, M.},
title= {Maternal grandmothers do go the extra mile: factoring distance and lineage into differential contact with grandchildren},
year = {2007},
journal = {Evolutionary Psychology },
volume = {5},
number = {4},
pages = {832--843},
}