References
- Heath TL. The thirteen books of Euclid's elements. New York: Dover Publications; 1956.
- Greenberg M. Euclidean and non-Euclidean geometry: development and history. San Francisco (CA): W.H. Freeman and Company; 1980.
- Gray J. Worlds out of nothing. London: Springer; 2007.
- Efimov NV. Higher geometry. Moscow: Mir Publishers; 1980.
- Bonola R. Non Euclidean geometry: a critical and historical study of its development. New York: Dover; 1955.
- Lambert M. Mémoire surQuelques Propriétés Remarquables des Quantités Transcendentes Circulaires etLogarithmiques. In: Pi: a source book. New York (NY): Springer; 2004.
- Lambert JH. Theorie der parallellinien. In: Stäckel P and Engel F, editors. Die Theorie der Parallellinien von Euklid bis auf Gauss, eine Urkundensammlung zur Vorgeschichte der nicht-euklidischen Geometrie. Leipzig: Teubner; 1786.
- Beltrami E. Saggio di interpretazione della geometria non-euclidea. Naples: Grande stabilimento tipografico di Franc. e Gennaro de Angelis; 1868.
- Hilbert D. Über Flächen von konstanter Krümmung. Trans Amer Math Soc. 1901;2:87–99.
- O'Neill B. Elementary differential geometry. revised 2nd ed. New York: Academic Press; 2006.
- Poincaré H. Science and hypothesis. New York: Walter Scott Publishing; 1905.
- Wartofsky M. Models: representation and the scientific understanding. Boston studies in the philosophy of science, vol. XLVIII. Boston (MA): Reidel Publishing Company; 1979.
- Wittgenstein L. Philosophical investigations. Oxford: Blackwell; 1958.
- Hohenwarter M. GeoGebra: ein softwaresystem fur dynamische geometrie und algebra der ebene. Salzburg: Paris Lodron University; 2002.
- Arzarello F, Olivero F, Paola D, et al. A cognitive analysis of dragging practices in Cabri environments. Zentralblatt für Didaktik der Mathematik. 2002;34(3):66–72.
- Lopez-Real F, Leung A. Dragging as a conceptual tool in dynamic geometry environments. Int J Math Educ Sci Technol. 2006;37(6):665–679.
- Jones K. Providing a foundation for deductive reasoning: students' interpretations when using dynamic geometry software and their evolving mathematical explanations. Educ Stud Math. 2000;44(1–2):55–85.
- Guven B, Karatas I. Students discovering spherical geometry using dynamic geometry software. Int J Math Educ Sci Technol. 2009;40(3):331–340.
- Junius P. A case example of insect gymnastics: how is non-Euclidean geometry learned? Int J Math Educ Sci Technol. 2008;39(8):987.