Cohomological interpretation of quadratic modular symbols
  Bayer and Blanco-Chac\'on have recently defined quadratic modular symbols for the Shimura curves X(D,N) attached to Eichler orders of level N of an indefinite quaternion rational algebra of discriminant D. In this paper, we give a cohomological interpretation of these quadratic modular symbols. Explicit computations for the homology of some Shimura curves are also provided. 
Pilar Bayer, Iv\'an Blanco-Chac\'on and Alberto F. Boix
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