↑"Classical", The Oxford Concise Dictionary of Music, ed. Michael Kennedy, (Oxford, 2007), Oxford Reference Online. Retrieved July 23, 2007.
↑Chew, Geffrey & Rastall, Richard. "Notation, §III, 1(vi): Plainchant: Pitch-specific notations, 13th–16th centuries". In Macy, Laura. Grove Music Online. Oxford Music Online. Oxford University Press.(subscription required)
↑Malm, W.P./Hughes, David W.. "Japan, §III, 1: Notation systems: Introduction". In Macy, Laura. Grove Music Online. Oxford Music Online. Oxford University Press.(subscription required)
↑IAN D. BENT, DAVID W. HUGHES, ROBERT C. PROVINE, RICHARD RASTALL, ANNE KILMER. "Notation, §I: General". In Macy, Laura. Grove Music Online. Oxford Music Online. Oxford University Press.(subscription required)
↑Middleton, Richard. "Popular music, §I, 4: Europe & North America: Genre, form, style". In Macy, Laura. Grove Music Online. Oxford Music Online. Oxford University Press.(subscription required)