@article{Danielsbacka2011,
author = {Danielsbacka, M. and Tanskanen, A.O. and Jokela, M. and Rotkirch, A.},
title= {Grandparental child care in Euope: Evidence for preferential investment in more certain kin},
year = {2011},
doi = {10.1177/147470491100900102},
journal = {Evolutionary Psychology},
volume = {9},
number = {1},
pages = {3--24},
}