Study of the Legend of Holy Grail’s Knight and Emperor Friedrich II by the European House of Andechs Meranien. From the Viewpoint Their Aim for Ending of International Religious War "the Crusades" in 12-13th Century. Mediterr. J. Soc. Sci. [Internet]. 2013 Oct. 1 [cited 2024 Jul. 18];4(10):160. Available from: https://www.richtmann.org/journal/index.php/mjss/article/view/1170