Ben Schmidt hat auch gemerkt, dass mit Google Books etwas nicht stimmt:
http://sappingattention.blogspot.com/2019/02/how-badly-is-google-books-search-broken.html
“Of those 8,000 books published before 2002, how many show up in the Google Books search result with a date filter before 2002?
Just five. Two books that have “set in stone” in their titles (and thus wouldn’t need a working full-text index), one book from 2001, and two volumes of the Congressional record. 99.95% of the books that should be returned in this search–many of which, in my experience, were generally returned four years ago or so–have vanished.”