http://www.ilo.org/global/publications/books/WCMS_605078/lang–en/index.htm
https://lawliberty.org/book-review/worth-more-than-gold/
https://www.brookings.edu/blog/future-development/2020/02/21/to-move-the-needle-on-ending-extreme-poverty-focus-on-rural-areas/?utm_campaign=Brookings%20Brief&utm_source=hs_email&utm_medium=email&utm_content=83727076
https://theconversation.com/alexander-von-humboldt-el-naturalista-que-se-arruino-por-contar-la-importancia-de-la-naturaleza-229577