Hi,
I have been facing problem on finding Mathematica packages. For example, there are videos, paper a notebook for System Identification, but there is no link to download or buy the package: library.wolfram.com/infocenter/Conferences/5451/ http://library.wolfram.com/infocenter/Conferences/6444/
Another example is the page http://library.wolfram.com/infocenter/Demos/4798/ where the link http://www.wolfram.com/products/applications/control/ to the package is just broken.