@article{Hofferth2003,
author = {Hofferth, S.L. and Anderson, K.G.},
title= {Are all dads equal? Biology versus marriage as a basis for paternal investment},
year = {2003},
doi = {10.1111/j.1741-3737.2003.00213.x },
journal = {Journal of Marriage and the Family},
volume = {65},
number = {1},
pages = {213--232},
}