Suchitphanit S. An Analytical Comparison of Beethoven’s Final Three Piano Sonatas: Opp. 109, 110, 111. MMJ [internet]. 2019 Apr. 1 [cited 2026 Sep. 10];1(2):52-64. available from: https://so04.tci-thaijo.org/index.php/mmj/article/view/181518