http://www.fismat.umich.mx/computacion/notas/introduccion/indice2.html#catorce

http://www.javabeginner.com/java-swing/java-jinternalframe-class-example

https://www.google.com.pe/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&ved=0CGcQFjAH&url=http%3A%2F%2Fdownload.java.net%2Fjavadesktop%2Fswingset3%2FSwingSet3.jnlp&ei=2xiXUZjOO9P_4AOpjIH4Bw&usg=AFQjCNELweKkSXOMmeFRi5LMD-RNkKFmYQ&sig2=-Payn60_Sj4BqfgsGqhQYg&bvm=bv.46751780,d.dmg