บุญอิต ส. “Rhetorical Essay on Beethoven S Ninth Symphony Emphasis on the Forth Movement: The History and the Influence of Friedrich Schiller S ‘Ode to Joy’ in the Beethoven S Symphony No.9 in D Minor, Op. 125”. Rangsit Music Journal, vol. 1, no. 1, Aug. 2018, pp. 7-13, https://so06.tci-thaijo.org/index.php/rmj/article/view/139122.