Millington, M. H. Subgroups of the classical modular group. (English) Zbl 0206.36801 J. Lond. Math. Soc., II. Ser. 1, 351-357 (1969). MSC: 11F06 PDFBibTeX XMLCite \textit{M. H. Millington}, J. Lond. Math. Soc., II. Ser. 1, 351--357 (1969; Zbl 0206.36801) Full Text: DOI
Millington, M. H. On cycloidal subgroups of the modular group. (English) Zbl 0169.10101 Proc. Lond. Math. Soc., III. Ser. 19, 164-176 (1969). PDFBibTeX XMLCite \textit{M. H. Millington}, Proc. Lond. Math. Soc. (3) 19, 164--176 (1969; Zbl 0169.10101) Full Text: DOI