visto da Tullio Pascoli
LA DEMOCRAZIA E LA LEGGE FERREA DELL’OLIGARCHIA (James Bryce) https://www.ibs.it/ebook/autori/Roberto%20Michels
POLITICAL PARTIES (Seymour Martin Lipset) https://www.amazon.com/Political-Parties-Sociological-Oligarchial-Tendencies/dp/168422022X/ref=as_li_ss_tl?ie=UTF8&linkCode=sl1&tag=theindepeende-20&linkId=84cb2537fbcc24d61f9cb68577c1edb2&language=en_US
ZUR SOZIOLOGIE DES PARTEIWESENS IN DER MODERNEN DEMOKRATIE https://www.amazon.de/dp/3520250047/ref=sr_1_1?dchild=1&keywords=robert+michels&qid=1586097273&sr=8-1