Wier 1940, p. 55. Wier, Albert Ernest (1940). "The Giraffe Piano". The Piano: Its History, Makers, Players and Music. Longmans, Green and Company. p. 55. OCLC27792371.
J. F. Bleyer: Historische Beschreibung der aufrechtstehenden Forte-Pianos, von der Erfindung Wachtl und Bleyers in Wien. in: Intelligenz-Blatt zur Allgemeinen Musikalischen Zeitung November 1811, Nº. XVII, Sp. 73–77 Giraffe piano, p. RA1-PA811, at Google Books
Martin Seuffert: Rechtfertigung. in: Intelligenz-Blatt zur Allgemeinen Musikalischen Zeitung May 1812, Nº. V, Sp. 21–22 Giraffe piano, p. PA337, at Google Books
Wier 1940, p. 55. Wier, Albert Ernest (1940). "The Giraffe Piano". The Piano: Its History, Makers, Players and Music. Longmans, Green and Company. p. 55. OCLC27792371.