Note that scraping, regardless of the level of permission, doesn't mean you can do anything you want with the content. Copyright still applies. But you can scrape it, and if your use falls under Fair Use or another caveat to the copyright laws then you can do ahead and do it without needing any permission from the authors.
I haven’t read volume 1, but apparently half of it is about data scraping, and I expect it to be similarly detailed. So if I were you, that’s where I’d start.
Another option is looking for “robots.txt” at Google Scholar and trying various keywords like “legality”, “scraping”, “case law”, etc.
[1] https://free.law/recap/faq
(full disclosure: assisting someone pursuing regulatory action against reddit in the EU for a separate issue from scraping, it's a valuable resource, but the folks who own and control it are meh)
