How to partition a drive and install both OSX Mavericks & Mountain Lion

I'm looking to partition my SSD on my Mid-2012 15" MacBook Pro Retina. I want to partition it so that around 130GB of my 256GB SSD is running OSX Mountain Lion as it is currently by restoring it via the external backup HDD I have and then 50GB of the SSD is running Mavericks, how might I be able to do this? Thanks!