Cook, 1993, Product description (blurb). «Beethoven's Ninth Symphony is acknowledged as one of the supreme masterpieces of the Western tradition. More than any other musical work it has become an international symbol of unity and affirmation.» Cook, Nicholas (1993). Beethoven: Symphony No. 9. Cambridge Music Handbooks. Cambridge: Cambridge University Press. ISBN0-521-39039-7.
Cook, Nicholas (1993b). «2. Early impressions». Beethoven: Symphony No. 9. Cambridge Music Handbooks. Cambridge: Cambridge University Press. pp. 26-47. ISBN978-0-521-39924-1. doi:10.1017/cbo9780511611612.003.
Cook, Nicholas (1993b). «2. Early impressions». Beethoven: Symphony No. 9. Cambridge Music Handbooks. Cambridge: Cambridge University Press. pp. 26-47. ISBN978-0-521-39924-1. doi:10.1017/cbo9780511611612.003.
Cook, Nicholas (1993b). «2. Early impressions». Beethoven: Symphony No. 9. Cambridge Music Handbooks. Cambridge: Cambridge University Press. pp. 26-47. ISBN978-0-521-39924-1. doi:10.1017/cbo9780511611612.003.
Noorduin, 2021. Noorduin, Marten (17 de mayo de 2021). «The metronome marks for Beethoven's Ninth Symphony in context». Early Music (journal)49: 129-145. ISSN0306-1078. doi:10.1093/em/caab005.
Ericson, John (10 de abril de 2010). «The Natural Horn and the Beethoven 9 "Controversy"». Horn Matters | A French Horn and Brass Site and Resource | John Ericson and Bruce Hembd(en inglés). Consultado el 6 de octubre de 2021.
Noorduin, 2021. Noorduin, Marten (17 de mayo de 2021). «The metronome marks for Beethoven's Ninth Symphony in context». Early Music (journal)49: 129-145. ISSN0306-1078. doi:10.1093/em/caab005.