Yale Russian Chorus - http://www.yale.edu/yrc/recordings.html (Kind of short recordings and only 3 or 4)
Russian Chamber Chorus of New York - http://www.rccny.org/WatchandListen.html (Really high quality and they're videos.)
Golosa - http://www.golosa.org/music (This one probably has the most music on it. Also it's the name of our book so it's gotta be good!)
Hope you enjoy this!