^Kraus, Herbert. Das große Buch der Musiktheorie. Bonn: Voggenreiter Verlag, 2012. Seite 28. ISBN 978-3-80240-936-3
^Bartel, Frank. Musiktheorie endlich verstehen. Berlin: Leu-Vlg Wolfgang Leupelt, 2015. Seiten 6-18. ISBN 978-3-89775-155-2
^Schulenberg, David. Music of the Baroque. New York: Oxford University Press, 2001. p. 72.. "(…) to determine the key of a Baroque work one must always analyze its tonal structure rather than rely on the key signature."
^Cooper, David. The Petrie Collection of the Ancient Music of Ireland. Cork: Cork University Press, 2005. p. 22. "In a few cases Petrie has given what is clearly a modal melody a key signature which suggests that it is actally in a minor key. For example, Banish Misfortune is presented in D minor, although it is clearly in the Dorian mode."