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."
