Libros gratis para escuelas

https://news.slashdot.org/story/17/04/19/224247/states-are-moving-to-cut-college-costs-by-introducing-open-source-textbooks?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Slashdot%2Fslashdot+%28Slashdot%29


https://www.oercommons.org/