@article{Shalizi2011,
author = {Shalizi, C.R. and Thomas, A.C.},
title= {Homophily and contagion are generically confounded in observational social network studies},
year = {2011},
doi = {10.1177/0049124111404820},
volume = {40},
number = {2},
pages = {211--239},
}