Comment by qingcharles

You can't, without spending a fortune to investigate the scarcity of some of the titles. I do a little work in this space and I don't know of anything destructively scanned that has zero other copies, but definitely some with single digit known copies, where no previous scan exists. Now there is one less physical copy, but a digital copy that none of us can access (except by tricking an LLM).

It's not just the big players buying up these archives, either. There are a lot of smaller players, especially in the OCR space, who are buying up huge swathes of works in languages which have much smaller digital footprints, e.g. Arabic.