[url=http://nsfnoyce.org/files/2013/06/1.13-GeoGebra.pdf]http://nsfnoyce.org/files/2013/06/1.13-GeoGebra.pdf[/url]
[url=http://www.maismatematica.com.br/blog/manual2.pdf]Bu, Lingguo and Schoen, Robert (2011). Model-Centered Learning. Pathways to Mathematical Understanding Using GeoGebra. Southern Illinois University, Carbondale, USA and Florida State University, Tallahassee, USA[/url]