The "PDF" files require the (free) Acrobat reader.
Note: If you are using an old version of Acrobat, you might get a "garbage display" when you click on a PDF link - all horizontal lines with little or no text.
This seems to be solved with recent versions of the Acrobat Reader - so if you have trouble, try downloading the latest version.
In addition, there are problems with the pdf reader that comes with Firefox - to read our pdf files without problem, we recommend that you reconfigure Firefox so as to use an external pdf reader, such as Acrobat Reader.
Here is how to do that:
1. At the top of the Firefox window, find and click on Options. (e.g. Tools > Options). 2. Select the Applications panel. 3. Find Portable Document Format (PDF) in the list and click on it to select it. 4. Click on the drop-down arrow in the Action column for the above entry and select the Use PDF reader name (e.g. Use Adobe Reader).
Another solution (for all browsers) is to just download the file and save it to a folder of your choice (right-click on the link and then "Save Link/Target As"...), and then open it (double click on the filename in "My Computer") in the usual way with Acrobat and it ought to look - and print - just fine.