1. Ahrens, W. (1901). Mathematische Unterhaltungen und Spiele. Leipzig: B. G. Teubner.
2. Alperin, R. C., & Lang, R. J. (2009). One-, two-, and multi-fold origami axioms. In R. J. Lang (Ed.), Origami4: Fourth international meeting of origami science, mathematics, and education (pp. 371–393). Natick, Massachusetts: A. K. Peters.
3. Avigad, J., Dean, E., & Mumma, J. (2009). A formal system for Euclid’s elements. The Review of Symbolic Logic, 2, 700–768.
4. Banks, J. A., & McGee Banks, C. A. (1989). Multicultural education. Needham Heights, MA: Allyn & Bacon.
5. Beloch, M. P. (1934). Alcune applicazioni del metodo del ripiegamento della carta di Sundara-Row. Atti dell’Acc. di Scienze, Mediche. Naturali e Matematiche di Ferrara, Serie II, 11, 186–189.