Burnham, Scott G.; Steinberg, Michael P. (2000). Beethoven and his world. [S.l.]: Princeton University Press. pp. 39–40. ISBN978-0-691-07073-5. Consultado em 4 de agosto de 2011
Newman 1970, p. 486. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617
Skowroneck 2002, p. 523. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Skowroneck 2002, p. 530-531. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Skowroneck 2002, p. 522. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Newman 1970, p. 489-490. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617
Winston 1993. Winston, David (1993). «The Restoration of Beethoven's 1817 Broadwood Grand Piano». The Galpin Society Journal. 46: 147–151. JSTOR842353. doi:10.2307/842353
Newman 1970, p. 491. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617
Newman 1970, p. 486. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617
Skowroneck 2002, p. 523. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Skowroneck 2002, p. 530-531. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Skowroneck 2002, p. 522. Skowroneck, Tilman (2002). «Beethoven's Erard Piano: Its Influence on His Compositions and on Viennese Fortepiano Building». Oxford: Oxford University Press. Early Music. 30 (4): 522–538. JSTOR3519211. doi:10.1093/em/XXX.4.523
Newman 1970, p. 489-490. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617
Winston 1993. Winston, David (1993). «The Restoration of Beethoven's 1817 Broadwood Grand Piano». The Galpin Society Journal. 46: 147–151. JSTOR842353. doi:10.2307/842353
Newman 1970, p. 491. Newman, William S. (1970). «Beethoven's Pianos versus His Piano Ideals». Journal of the American Musicological Society. 23 (3): 484–504. JSTOR830617. doi:10.2307/830617