REAL SYSTEM OF UNITS
By using only the magnitudes of space and time, the Real System of Units provides a simple management of different measurements and an immediate check of the calculations. However, its main feature is to allow understand the different measured phenomena.
Spanish:https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0Bx_F2PuqpjjgNzQ0ZDg4ZjUtYWYxYS00OWJlLThjOTQtZDM1NWU4NzY1MGVi&hl=en