http://www.ted.com/talks/lang/eng/nicholas_christakis_how_social_networks_predict_epidemics.html
http://www.ted.com/talks/lang/eng/nicholas_christakis_the_hidden_influence_of_social_networks.html
http://www.ted.com/talks/steven_strogatz_on_sync.html
https://www.ted.com/talks/albert_laszlo_barabasi_the_real_relationship_between_your_age_and_your_chance_of_success