
https://www.dbresearch.de/PROD/RPS_DE-PROD/PROD0000000000523908/Deutschland%3A_Konjunktur_kurzgefasst.PDF

https://www.cia.org.uk/news/details/Key-sector-of-the-economy-questions-the-budget-commitment-to-manufacturing

https://theconversation.com/la-paradoja-de-la-abundancia-como-se-explica-que-un-pais-rico-en-recursos-no-genere-crecimiento-economico-207778