References
Associated Board of the Royal Schools of Music (ABRSM) (2018) Music Theory exams [online], London, ABRSM, https://gb.abrsm.org/ en/ our-exams/ music-theory-exams/ [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] (Accessed 16 July 2020).
Taylor, E. (1989) The AB Guide to Music Theory, Part I, London, Associated Board of the Royal Schools of Music.