It seems also to be available from the publisher Hartker Verlag. Search Nocturnale Romanum.
It may, of course, be that you have already tried these sources and found it to be out of print; its enterprising editor, Peter Holger Sandhofe died suddenly in 2006 at quite a young age, and it may be that it has been allowed to go out of print. It is an extensive and wonderful resource, providing as it does the entire run of responsories for the night office of the Roman Rite, something otherwise not available in modern edition.
I've ordered a copy in the last month from the publisher, so it should still be available from them. bgeorge77 may be looking for a used one so as to cut down the substantial expense?
Thanks for the links. As for the gregobase link, it doesn't have the entire nocturnal but just bits of it. I am trying to source for all the referenced chants from his Ordo Responsorialis.
The slides are of low-resolution but it's not entirely illegible. Perhaps one day, with everyone's contribution, every page will be re-set in digital form (Only some of them on the website have been). I do wonder nevertheless if anyone is willing to part with a copy for a price. Let me know....
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