People always talk about fixed matches, but the question you should ask is Are there fixed matches? Hell yes. They exist in every league of the world especially English league, Romania league, Norway, US, Japan and so on.
First rule - you won't find fixed matches on the internet.
From what I know, these kind of matches are not sold on a free market for a simple reason - the more people know about the match, the less you're making some profit out of it ( and maybe some guy from UEFA buys your match and next day you're in prison). Infos about fixed matches go only to trustable persons