http://files.centro-demaestros-cuautitlan1524.webnode.mx/200000125-3eebe40e26/Ecolog%C3%ADa%20Humana.pdf
https://www.redalyc.org/pdf/1910/191019350008.pdf
http://agro.unc.edu.ar/~extrural/HerreraEspacioTecn.pdf
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https://books.google.es/books?hl=es&lr=&id=cSvEDgAAQBAJ&oi=fnd&pg=PR2&dq=principios+de+comunismo&ots=_QI_eeMtDM&sig=gPUOXAOL51Eg61cm7RTbWCSsvik#v=onepage&q=principios%20de%20comunismo&f=false
http://www.revistaeconomiacritica.org/sites/default/files/5_REC13_Nota_J_Catalan.pdf
https://www.earthmagazine.org/article/june-9-1938-huang-he-diversion-largest-act-environmental-warfare-history
http://www.scielo.org.mx/scielo.php?pid=S0187-893X2012000200009&script=sci_abstract&tlng=en
https://www.independent.co.uk/news/uk/politics/the-green-party-a-short-history-9878649.html
https://www.sciencedirect.com/science/article/pii/S004896971301173X
