[list=1][*]ABAR, Celina A.P. [i]O uso[/i][i]do GeoGebra na investigaçao da geometría elíptica.[/i] Actas del VI Congreso Uruguayo de Educación Matemática.[/*][*][color=#000000]COXETER, H.S.M. [/color][i]The Non-Euclidean Symmetry of Escher's Picture 'Circle Limit III'[/i]. Leonardo, Vol. 12, No. 1, pp. 19-25. Published by The MIT Press.[/*][*] COXETER, H.M.S. The trigonometry of hyperbolic tessellations.[url=https://cms.math.ca/cmb/]Canad. Math. Bull.[/url] [url=https://cms.math.ca/cmb/v40/]40[/url][color=#666666](1997), 158-168. 1997.[/color][/*][*][color=#333333]DUNHAM, Douglas. [/color][i]Some Maths behind the Circle Limit's Patterns.[/i] University of Minessotta.[/*][*][color=#333333]DUNHAM, Douglas. [/color][color=#666666][i]A Circle Limit III Calculation. [/i][/color]University of Minessotta.[/*][*]GREENBERG, M. [i]Euclidean and Non-Euclidean Geometry. Third edition.[/i] W.H. Freeman Inc. New York, 1993.[/*][*]RODRÍGUEZ TRÍAS, Ujué. Herramientas Hiperbólicas y Proyectivas con GeoGebra. TFM, Universidad de Cantabria.[/*][/list][br][br][br][br][br][br]