@article{Kohler2011,
author = {Kohler, H.-P. and Behrman, J.R. and Schnittker, J.},
title= {Social science methods for twins data: Integrating causality, endowments, and heritability},
year = {2011},
doi = {10.1080/19485565.2011.580619},
volume = {57},
number = {1},
pages = {88--141},
}