@article{McPherson2001,
author = {McPherson, M. and Smith-Lovin, L. and Cook, J.M. },
title= {Birds of a feather: Homophily in social networks},
year = {2001},
doi = {10.1146/annurev.soc.27.1.415},
journal = {Annual Review of Sociology },
volume = {27},
number = {1},
pages = {415--444},
}