I'm going to go through my back posts, as I get time, and fix any others, most of which (IIRC) are in Science (magazine). Meanwhile, here's a trick you can use for most (hopefully all) of the Science links like this in my posts, and likely a great number of other older articles there.
- Go to HighWire Press, which will bring up a search screen (if it doesn't, you'll have to navigate around the site till you find one).
- Paste the title of the article you want to read into the field labeled Anywhere in Text:, and click on the phrase selector.
- Click the Search button.
- Scan down the resulting list of articles until you find one with a "this article is FREE" panel under it. To be fair, you should pick a free article related to the reason you want to read one you're after. (Even better if you want to read it too.)
- Click on the Full text link at the right (the PDF won't work, if that's all there is, you need another choice).
- Drop down to the footnotes, and find the one for the title you're after. (I normally use a text search in the browser.)
- If there's a link for "Free full text", click it. If there isn't, you'll have to try another. (I've always seen one so far.)
So far, this has worked for me, although most of the papers were those I followed free text links to before, and only with Science. And only with older papers.
Of course, this may not work forever. And there may be other tricks needed with other publishers, although it may work for articles in other magazines published by HighWire. I guess it depends how eager you are to read an article, how much effort you'll put into finding a way to it without paying. It's different for me, since I need to make them available to readers.