Obituary from Musical America (June 26, 1915): "The Hamburg conductor C. A. Hermann Wolff, died recently. He was the author of a valuable piano method, "Der Kinderfreund" (The Child's Friend), which has been translated into eight languages and of which 100,000 copies are in circulation. He was the composer of piano teaching music, much of which was published under the name of C. A. Hermann. Such pieces as his "Tonbilder," "Traumbilder" and "Der Maskenbal" have been much used for piano students in the early grades. Mr. Wolff made many transcriptions for the piano of works of old and modern masters. He was also a music critic and his writings which appear in 'Reklam's Universal Bibliotek' are widely known."