I'm sitting with Bill Egan's fine book "The Doeberl Cup" in front of me - BUY IT! - and looking at his sources.
I expect that Cathy Chua's "Australian Chess at the Top" is more or less impossible to get.
What about "Important Moments in Chess: Canberra 1988 Doeberl Cup" from Johnny [Johny] Bolens(!)?? Never heard about it, to be honest. I suppose this is also an impossible one.