1. Imin Chen and Chris Cummins, Elliptic curves with nonsplit mod 11 representations, Math. Comp. 73 (2004), no. 246, 869–880 (electronic).[MR]
  2. C. J. Cummins, Congruence subgroups of groups commensurable with PSL(2,Z) of genus 0 and 1, Experiment. Math. 13 (2004), no. 3, 361–382.[MR]
  3. C. J. Cummins, On conjugacy classes of congruence subgroups of PSL(2,R), LMS J. Comput. Math. 12 (2009), 264–274.[MR/doi]
  4. C. J. Cummins and S. Pauli, Congruence subgroups of PSL(2,Z) of genus less than or equal to 24, Experiment. Math. 12 (2003), no. 2, 243–255.[MR]