Z.library was terminated by the US government yesterday, but it seems that one tiny window is still open. Thanks to Tor Project https://www.torproject.org/. Tested and it worked out: 1) download a Tor browser on Tor's site; 2) fill this .onion address of z.library: zlibrary24tuxziyiyfr7zd46ytefdqbqd2axkmxm4o5374ptpc52fad.onion; 3) wait for seconds; 4) z.library is back
However, direct download is not possible anymore, only 'send to email' works. (Not a big deal).