@article{Christakis2008,
author = {Christakis, N.A.  and Fowler, J.H. },
title= {The collective dynamics of smoking in a large social network},
year = {2008},
doi = {10.1056/NEJMsa0706154},
journal = {New England Journal of Medicine },
volume = {358},
number = {21},
pages = {2249--2258},
}