Integral points of a modular curve of level 11
  Using lower bounds for linear forms in elliptic logarithms we determine the integral points of the modular curve associated to the normalizer of a non-split Cartan group of level 11. As an application we obtain a new solution of the class number one problem for complex quadratic fields. 
Ren\'e Schoof, Nikos Tzanakis
math.NT