Question: Carry On is a 4-CD career retrospective box set by Stephen Stills, including tracks with the vocal folk rock supergroup named what?
Sentence (from "Buffalo Springfield (box set)"): Of the four CDs, the first three represent the actual box set while the fourth CD contains the band's first two albums, all but two tracks of which had already appeared in identical versions elsewhere on the first three CDs.
Relevant evidence: No