@article{Hogan1993,
author = {Hogan, D.P. and Eggebeen, D.J. and Clogg, C.C. },
title= {The structure of intergenerational exchanges in american families},
year = {1993},
doi = {10.1086/230194},
journal = {American Journal of Sociology},
volume = {98},
number = {6},
pages = {1428--1458},
}