@inbook{Hrdy2005,
author = {Hrdy, S.B.},
title= {Cooperative breeders with an ace in the hole},
year = {2005},
editor = {Voland, E.},
editor = {Chasiotis, A.},
editor = {Schiefenhovel, W. },
booktitle = {Grandmotherhood: The evolutionary significance of the second half of female life},
address = {New Brunswick},
publisher = {Rutgers University Press},
}