How to access older osx software in new SDK page ?

I am having a hard time finding how to download older osx software from the new Member Center SDK section.

Is access to all pre yosemit software gone ?

I had no problem to find older OSX like Yosemite. Under downloads you will see the older OSX bit down the page.

I can see Yosemite but I can't see anything prior to that like XSAN etc.

How to access older osx software in new SDK page ?
 
 
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