Where can you get early Barenaked Ladies songs?

I was wondering if there are any ways to get the earliest songs by the Barenaked Ladies such as the songs in the first 'demo tape' albums Buck Naked (aka "The Yellow Tape") or Barenaked Lunch (aka "The Pink Tape"). The song in particular that I'm hoping to find is "The Trouble with Tracy". However, any of these songs from the Pink and Yellow tapes are extremely rare. Does anyone know where to get them? Possibly itunes or some other mp3 store...?