http://www.repubblica.it/politica/2015/09/27/news/morto_pietro_ingrao-123799642/?ref=HREA-1
https://marteau7927.wordpress.com/2015/03/30/pietro-ingrao-compie-100-anni/
http://www.repubblica.it/politica/2015/09/27/news/morto_pietro_ingrao-123799642/?ref=HREA-1
https://marteau7927.wordpress.com/2015/03/30/pietro-ingrao-compie-100-anni/