A selective list of acquistion and contracting portals (lists of usefull links).
If you are able to find the website of the program office and/or the contractor for the system or program you are researching, these can be a gold mine. Students are discouraged from attempting to contact the program officers, however.
You may need to do some digging to identify the program officer. Often you can find this information using a search engine such as Google, but if you have difficulty try using the source listed below.