Geodesic
Subgroups of infinite index in the modular group
Glasgow mathematical journal, Tome 19 (1978) no. 1, pp. 33-43

Voir la notice de l'article provenant de la source Cambridge University Press

The modular group Г is the group of integral bilinear transformations of the extended complex plane which preserve the upper half-plane. It has the presentation 〈x, y:x2 = y3 = 1〉, and the generators can be chosen so that u = xy maps z to z + 1. 
Stothers, W. W. Subgroups of infinite index in the modular group. Glasgow mathematical journal, Tome 19 (1978) no. 1, pp. 33-43. doi: 10.1017/S0017089500003347
@article{10_1017_S0017089500003347,
     author = {Stothers, W. W.},
     title = {Subgroups of infinite index in the modular group},
     journal = {Glasgow mathematical journal},
     pages = {33--43},
     year = {1978},
     volume = {19},
     number = {1},
     doi = {10.1017/S0017089500003347},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003347/}
}
TY  - JOUR
AU  - Stothers, W. W.
TI  - Subgroups of infinite index in the modular group
JO  - Glasgow mathematical journal
PY  - 1978
SP  - 33
EP  - 43
VL  - 19
IS  - 1
UR  - http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003347/
DO  - 10.1017/S0017089500003347
ID  - 10_1017_S0017089500003347
ER  - 
%0 Journal Article
%A Stothers, W. W.
%T Subgroups of infinite index in the modular group
%J Glasgow mathematical journal
%D 1978
%P 33-43
%V 19
%N 1
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003347/
%R 10.1017/S0017089500003347
%F 10_1017_S0017089500003347

[1] 1.Harary, F., Graph theory (Addison-Wesley, 1969). Google Scholar | DOI

[2] 2.Lehner, J., Discontinuous groups and automorphic functions (Amer. Math. Soc, 1964). Google Scholar | DOI

[3] 3.Mason, A. W., On a theorem by Leon Greenberg, Proc. Amer. Math. Soc. 23 (1969), 18–23. Google Scholar

[4] 4.Millington, M. H., On cycloidal subgroups of the modular group, Proc. London Math. Soc. (3), 19 (1969), 164–176. Google Scholar | DOI

[5] 5.Millington, M. H., Subgroups of the classical modular group, J. London Math Soc. (2), 1 (1969), 351–357. Google Scholar

[6] 6.Stothers, W. W., Subgroups of the modular group, Proc. Cambridge Philos. Soc. 75 (1974), 139–153. Google Scholar

[7] 7.Stothers, W. W., Impossible specifications for the modular group, Manuscripta Math. 13 (1974), 415–428. Google Scholar

[8] 8.Tretkoff, C., Nonparabolic subgroups of the modular group, Glasgow Math. J. 16 (1975), 91–102. Google Scholar

Cité par Sources :