How can I get a OSX mountain lion installer for deployment testing?

I have a macmini which came with Mountain Lion preinstalled as from factory. I need to create a virtual machine on this macmini (OSX host/OSX guest) with the same version for end-user deployment testing. I went to the apple store to get the installer, but I can only get mavericks, and I want to test deployment on 10.8. How can I get a ML installer so I can use vmware or virtualbox to install osx in the virtual image?

Developers registered with Apple's Mac Developer Program can download older editions of Mac OS X for development and testing purposes.

The screenshot below shows OS X Mountain Lion is still available to developers.

You can purchase Mountain Lion from the Apple Store.

• http://store.apple.com/us/product/D6377Z/A/os-x-mountain-lion

This gives you a code which lets you redeem Moutain Lion from the Mac App Store and download the installer.