CA Products Documentation is available in SupportOnline Home Page, choosing option 'Documentation' under tab 'Menu' , at the below URL Link
In the search windows it is possible to locate for each CA Product the related set of Documentation Manuals sorted by the supported Releases.
How to retrieve from this same location the Documentation Guides of the old and unsupported Releases ?
Z/OS - Mainframe Products
This is possible selecting the light blue title: