Years ago, I tried to retrieve a webpage link[1] that had an important article to encryption and the website had a redesign and all of their articles were removed.
I reached out to them later and asked if they had a copy of the article, or knew where I could get one, but they reported that they no longer have any of that. The same for a commercial that my father was in for a local mall, the mall was purchased by another company and lost ties with the media company that shot the commercial-- this media company is no longer around and thus no more archives.
Not necessarily and it depends a lot on what the materials were. IEEE publications were mentioned, it was founded in 1963 and there's a good chance that anything from the first 10 years may no longer be in archives unless donated back by a recipient.
I'd probably have more faith that IEEE publications still existed somewhere in some form. But the vast majority of publications either don't exist at all or they exist only in physical form someplace and aren't readily accessible.
I reached out to them later and asked if they had a copy of the article, or knew where I could get one, but they reported that they no longer have any of that. The same for a commercial that my father was in for a local mall, the mall was purchased by another company and lost ties with the media company that shot the commercial-- this media company is no longer around and thus no more archives.
[1] it would be nice if anyone could recover this text https://www.100tb.com/blog/security-performance-serpent-ciph...