Publishers can opt out of the book indexing, too (kind of like robots.txt) <a href="https:&#x2F;&#x2F;www.google.com&#x2F;googlebooks&#x2F;publisher_library.html" rel="nofollow">https:&#x2F;&#x2F;www.google.com&#x2F;googlebooks&#x2F;publisher_library.html</a>