Le Zeppelin IV is the common, but unofficial name of the untitled fourth album of English rock band Led Zeppelin. It was released on November 8, 1971. It has no official title printed anywhere on the album, but is called Led Zeppelin IV after the band's previous three albums. Atlantic Records catalogs have used the names Four Symbols ( ) and The Fourth Album; it has also been referred to as Zoso, which the first symbol appears to spell. Led Zeppelin guitarist Jimmy Page frequently refers to the album in interviews as Led Zeppelin IV, while singer Robert Plant thinks of it as "the fourth album, that's it". It is one of the best-selling albums in history, with over 23 million units sold in the United States, third most by any artist of all-time.