https://slideplayer.es/slide/10180707/
https://letras.unmsm.edu.pe/wp-content/uploads/2018/11/PROGRAMA-FINAL-CIIUI-PERU-2019-ENERO.pdf
https://prezi.com/rjpjldidgdxq/systemas-blandos/
http://www.mundoarchivistico.com/?menu=articulos&id=480
https://docplayer.es/7152909-Universidad-autonoma-de-san-luis-potosi.html