López Vílchez, Inmaculada. “Hermann Graf and the Proportion in Art: Old Proposals for Research Today”. Revista de Bellas Artes. Artes plásticas, estética, diseño e imagen, no. 10 (April 12, 2012): 15–40. Accessed November 11, 2026. https://www.ull.es/revistas/index.php/artes/article/view/5298.