
https://www.mckinsey.com/industries/technology-media-and-telecommunications/our-insights/rules-of-engagement-winning-with-the-basics-in-digital-telecommunications

https://www.imf.org/-/media/Files/Countries/ResRep/ECC/corporate-liquidity-and-solvency-in-europe-feb-12-2021-v3.ashx

https://theconversation.com/solo-el-11-5-de-la-economia-de-la-union-europea-es-circular-como-aumentar-el-porcentaje-223372