*[Curso de Programación Android](http://www.sgoliver.net/blog/wp-content/uploads/2011/11/Manual-Programacion-Android-SgoliverNet-v3-muestra.zip)(PDF) by Salvador Gómez Oliver
###Assembly Language
*[Machine Code for Beginners](http://www.worldofspectrum.org/infoseekid.cgi?id=2000227)(PDF) by Lisa Watts and Mike Wharton [Z80 and 6502 CPUs]