Strange.
It does work fine here.
Maybe: right mouse click > Save link/target as" might work for your?

Another link:
http://www.scene.org/~esa/merlib/Mueller.pdf

I must admit that viewing this document online in a web browser does not always work. So downloading it first will do the trick.

If this still does not work for you I can sent it to Aeron. But I don't have his mail address.

Steven