@article{Smits2003,
author = {Smits, J.},
title= {Social closure among the higher educated: Trends in educational homogamy in 55 countries},
year = {2003},
doi = {10.1016/S0049-089X(02)00049-2},
journal = {Social Science Research},
volume = {32},
number = {2},
pages = {251--277},
}