Library of Congress is supposed to have a copy of everything registered for copyright - but may discard items after 30 years. People report retrieving long-lost software by inspecting the copyright registration, for instance. However its website points to worldcat.org and see: "IBM OS/VS VTAM : reference summary"? only 3,398 miles from Boston at Biblioteca de la Universidad Complutense de Madrid. And so on. It is hard to find if this item is indeed "GX27-0034".
Perhaps neither Washington nor Madrid are helpful, but along the way there were manuals that said they would apply to MVS as well as MVS/XA and much more there.
Regards,
Laird Heal
