Is there a reliable source or story proving the DEA has worked with the Sinoloa Cartel?

Just read a story put out by Vice that suggests the legalization of the marijuana industry has hurt the Mexican cartel financially. It doesn’t say in the story that some of the cartel are already moving to the legalized cities which is a good story in itself.

But yes back to the OP, are there multiple sources with reliable backgrounds proving the DEA has worked with the Mexican Cartel? Just curious, because the source I’ve read it from was Reuters.com