*Aristotle,
Physics, ii. 454;
On Parts of Animals, ii. 459;
Treatise on Perspective (attributed to him in Vincent of Beauvais, Spec. Hist. iii. 84), v. 378;
Secretum Secretorum (attributed to Aristotle), v. 433.
Arnoldus de Villa Nova (or Villanovanus, 13th century), v. 432.
Arthurian Romances, v. 314, 374;
and see Lancelot, Tristram.
Augustine, St. (Bp. of Hippo, A.D. 345-430),
De Civitate Dei, iii. 331; v. 462, 463, 468;