@article{PMIHES_1993__78__187_0, author = {Schwartz, Richard Evan}, title = {Pappus's theorem and the modular group}, journal = {Publications Math\'ematiques de l'IH\'ES}, volume = {78}, year = {1993}, pages = {187-206}, zbl = {0806.57004}, language = {en}, url = {http://dml.mathdoc.fr/item/PMIHES_1993__78__187_0} }
Schwartz, Richard Evan. Pappus's theorem and the modular group. Publications Mathématiques de l'IHÉS, Tome 78 (1993) pp. 187-206. http://gdmltest.u-ga.fr/item/PMIHES_1993__78__187_0/
[B] The Geometry of Discrete Groups, Springer-Verlag, 1983.
,[H] Geometry and the Imagination, Chelsea Publishing Company, 1950.
and ,[T] The Geometry and Topology of Three-Manifolds, Princeton University Lecture Notes, 1978.
,