[1] - Book [2] - Book Chapter [3] - Website[4] - Journal
- ^ Johnston, Richard; Boak, Dick (2009). Martin Guitars: A Technical Reference, Volume 2. New York: Hal Leonard Books. pp. 2–14. ISBN 978-1423439820.
{{cite book}}: no-break space character in|title=at position 16 (help) - ^ Gerkan, Teja; Simmons, Michael; Ford, Frank; Johnston, Richard (2003). "3". Acoustic Guitar. Wisconsin: Hal Leonard. p. 24. ISBN 0-634-07920-4.
- ^ "How to Read Sheet Music: Guitar Theory, Ear Training, & Reading". Guitarlessons.com. 2019. Retrieved 6 April 2020.
{{cite web}}: CS1 maint: url-status (link) - ^ Alves, Julio (2015). "History of the Guitar". Marshall Digital Scholar. 12: 3.