https://en.wikiversity.org/wiki/Introduction_to_Programming
https://openclassrooms.com/courses/aprende-a-programar-con-javascript/introduccion-a-la-programacion
http://librosweb.es/libro/javascript/capitulo_1.html
https://www.codecademy.com/es/tracks/javascript-traduccion-al-espanol-america-latina-clone