Woo to WoO, to mean "works without number of Opus") is a short-sighted, wrote of the genre know that for numbering some works without number "opus" Ludwig van Beethoven goes to work. For example, in the use of "Wu" or WoO., the specifications of the famous for the Elysee's to the German, this form can write:
WoO 59: Für Elise Klavierstück in a-Moll
WoO 59: Für Elise Bagatelle (Poco moto) in A minor