SUB-HYPERELLIPTIC CURVES X<sup>+</sup><sub>1</sub>(N)

M. Furumoto and Y. Hasegawa, Hyperelliptic quotients of modular curves $X_0$(N), Tokyo J. Math. 22 (1999), no. 1, 105-125. https://doi.org/10.3836/tjm/1270041616
Y. Hasegawa, Hyperelliptic modular curves $X^{\ast}_0$ (N), Acta Arith. 81 (1997), no. 4, 369-385. https://doi.org/10.4064/aa-81-4-369-385
D. Jeon and C. H. Kim, Bielliptic modular curves $X_1$(N), Acta Arith. 112 (2004), 75-86. https://doi.org/10.4064/aa112-1-5
D. Jeon, C. H. Kim and E. Park, On the torsion of elliptic curves over quartic number fields, J. London Math. Soc. 74 (2006), 1-12. https://doi.org/10.1112/S0024610706022940
C. H. Kim and J. K. Koo, The normalizer of $\Gamma_1$(N) in $PSL_2$(R), Comm. Algebra, 28 (2000), no. 11, 5303-5310. https://doi.org/10.1080/00927870008827156
C. H. Kim and J. K. Koo, Estimation of genus for certain arithmetic groups, Comm. Algebra, 32 (2004), no. 7, 2479-2495. https://doi.org/10.1081/AGB-120037394
J.-F. Mestre, Corps euclidiens, unites exceptionnelles et courbes elliptiques, J. Number Theory 13 (1981), no. 2, 123-137. https://doi.org/10.1016/0022-314X(81)90001-9
A. Ogg, Hyperelliptic modular curves, Bull. Soc. Math. France 102 (1974), 449-462.

SUB-HYPERELLIPTIC CURVES X+1(N)