And search the archives of the UGA mailing list (SPSSX-L) via listserv.uga.edu. AFAICT, you have to sign in to carry out a search there.
Posts from the period when the Nabble forum was joined to the mailing list should appear in both places, although even in that period, I believe there may have been posts to Nabble (possibly from people who had not joined the mailing list) that did not go through to the actual mailing list.
While we're at it, let's also note that you can search the archives of the comp.soft-sys.stat.spss usenet group here:
PLEASE NOTE THE FOLLOWING: 1. My Hotmail account is not monitored regularly. To send me an e-mail, please use the address shown above.
2. The SPSSX Discussion forum on Nabble is no longer linked to the SPSSX-L listserv administered by UGA (https://listserv.uga.edu/).