According to this tweet [1] there are also audio tapes available, I haven't been able to get them (yet). I did send a mail to nbl@aip.org if they would consider to put a copy on the site.<p>[1] <a href="https://twitter.com/aip_history/status/1465408218507759627" rel="nofollow">https://twitter.com/aip_history/status/1465408218507759627</a>