Just go into google, and type the search:
Huerlimann site:http://www.tractorbynet.com
It will pick up a few links.
Of course, you can use the search function at the top right of the page too.
If you put in all 4 tractor brands in to the search, it will use the "or" function, and search for all of them.
Google will do the "or" function using the word or.
Try the following in Google:
Meili OR Buehrer OR Huerlimann OR Bucher site:http://www.tractorbynet.com