Guenter Ciessow

Günter Cießow (1934-2024) was a german 4 dan player, who won the European Championship in 1960 and the German Championship in 1960 and 1972. He learned to play Go in 1947 from Felix Dueball. In 2008 he published a book about Dueball ("Felix Dueball. Go-Pionier aus Berlin. Eine Reminiszenz aus "Go"-licher Sicht.")

See also: https://de.wikipedia.org/wiki/G%C3%BCnter_Cie%C3%9Fow