I have both those books you mention. A good copy of '21 Up' is quite valuable, especially if it's still got the DJ. It's a great read but a shame it cuts off when he still had one more World Championship left to win. As well as 'Sarajevo to Novi Sad', I also own Uzorinac's 'From London 1926 do Sarajevo 1973' (which I also spent ages translating with Google - not a job I'd recommend unless you're a TT HJ (History Junkie) like me
). Somewhere out there are Uzorinac's books on Stipancic and Croatian TT, but I'll save translating them for my old age.
One good shortlived magazine was the British 'Table Tennis' (well, there's an original title) - subtitled 'The Voice of British TT', which ran alongside TTNews during the late 70s and early 80s - a good read. I've got all of those somewhere.
'Table Tennis News' (ETTA mag) is all online now via the English TT site, thanks to some patient voluntary work. Quite a feat.