@inbook{Euler2008,
author = {Euler, H.A. and Michalski, R.L. },
title= {Grandparental and extended kin relationshps},
year = {2008},
editor = {Salmon, C.A.},
editor = {Shackelford, T.K.},
booktitle = {Family relationships: An evolutionary perspective},
address = {New York},
publisher = {Oxford University Press},
pages = {230--256},
}