Tài liệu tham khảo WikiPedia: Gustave_Le_Bon http://socserv.socsci.mcmaster.ca/~econ/ugcm/3ll3/... http://socserv.mcmaster.ca/econ/ugcm/3ll3/lebon/so... http://nsl-archiv.com/Buecher/heil.php?text=le+bon... http://dly.free.fr/site/article.php3?id_article=45 https://www.gutenberg.org/author/Gustave_Le_Bon
