Why the links no longer work

Many of the links to the literature on this blog's homepage no longer function, unfortunately, because of an apparent clamp-down by the original journals, or at least some of them, which forced the people operating the sites where they resided to take them down or behind a firewall. 

I think it is especially unfortunate that the journal publishers are so touchy in the case of the sort of physics literature relevant to my work.  It is often decades old and probably not of very wide interest.
 It's unlikely anyone will be trying or at least succeeding in making a monetary profit through posting it.  Neither of the two sites I used were commercial, in any case.

Many of the links were to papers on arxiv.org and so will continue to work indefinitely.  However, this covers only papers from the last 10-15 years for rhe most part, and many of the relevant papers to the topics of this blog are of course much older.

I plan to eventually replace the non-working links with working ones, but they will have to go to places where a subscription or payment will be needed to access the article.  However, usually at least the abstract is available.