I don’t have a direct answer, but I will say be careful about giving them to Goodwill or what-have-you, or at least check first. I donated a mound of great contemporary books and the guy receiving them said they throw out anything that has marks on the page side or any wear on the cover.

Not to say all thrift shops toss them, but some do.

Edit: Look for local “free libraries”! Some cities will have random little boxes put up around neighbourhoods, and those won’t get scrapped.