So the “Sanctum Gradale”, the Holy Grail, can really be a stone, a dish, or a round table (…). Vide Journal of the Warburg and Courtauld Institutes, tom. 19, 1956, p. 45, 49
Lucas Waddingus (ed.): Beati patris Francisci Assisiatis opuscula. Antverpiae 1623, p. 328
Eduard Brinckmeier (ed.): Glossarium diplomaticum, tom. 2, Hamburgi et Gothae 1856, p. 291