On Shafarevich-Tate groups and the arithmetic of Fermat Curves
  We extend the results of the first author on nontrivial elements in the Shafarevich-Tate group of the jacobian of a quotient of a Fermat curve of prime degree, and use the methods of the second author to derive a result bounding the quadratic points on the Fermat curve of degree 19. 
William G. McCallum and Pavlos Tzermias