@article{Roberts1991,
author = {Roberts, R.E. and Richards, L.N. and Bengtson, V.L.},
title= {Intergenerational solidarity in families untangling the ties that bind},
year = {1991},
doi = {10.1300/J002v16n01_02},
volume = {16},
number = {1–2},
pages = {11--46},
}