download Mac OS X 10.9

If you have previously purchased Mavericks, then Applications -> App Store -> Purchases

If you never purchased and downloaded Mavericks in the past, then you cannot download Mavericks, as Apple has stopped offering Mavericks for new downloads.

The one possibility is to make a Genius Bar appointment at your local Apple store and ask if they would install Mavericks for you (this may or may not work)

You can have a look here: http://www.macworld.co.uk/how-to/mac-software/how-install-download-old-versions- of-mac-os-x-3629363/ maybe helps to clarify.

I'm afraid that there is no link!