 | from the original on 31 October 2018. Retrieved 27 November 2017. "Prodotto interno lordo". Comune di Bologna. Archived from the original on 31 December 2019... 197 KB (17,979 words) - 21:45, 25 April 2024 |
 | Big Think. Retrieved 2018-06-25. Powerful Earthquakes in Italy. "Prodotto interno lordo lato produzione – dati territoriali (milioni di euro) – edizioni... 45 KB (3,814 words) - 20:04, 21 April 2024 |
 | from the original on 31 October 2018. Retrieved 27 November 2017. "Prodotto interno lordo". Comune di Bologna. Archived from the original on 31 December 2019... 20 KB (2,417 words) - 10:27, 23 February 2024 |