1. Abbott, E. A. (1884). Flatland: A romance in many dimensions. Dover Thrift Edition. (1992 unabridged). Retrieved August 29, 2017 from https://ia802708.us.archive.org/9/items/flatlandromanceo00abbouoft/flatlandromanceo00abbouoft.pdf
2. Aristotle. (1984). In J. Barnes (Ed.), The complete works of Aristotle: Categories (Vol. I). Princeton University Press. An equally serviceable free version with Bekker references is at: https://static1.squarespace.com/static/58d6b5ff86e6c087a92f8f89/t/5913d191f7e0ab9113b8884e/1494471072597/Complete_Works_of_Aristotle.pdf
3. Ashby, R. (1954). Design for a brain. Wiley. http://rossashby.info/Ashby%20-%20Design%20for%20a%20Brain%20-%20The%20Origin%20of%20Adaptive%20Behavior.pdf
4. Badiou, A. (2008). Number and numbers (MacKay, R., Trans.). Cambridge: Polity Press. https://philarchive.org/archive/BARABK
5. Binary Number. (2022). https://en.wikipedia.org/wiki/Binary_number#Western_predecessors_to_Leibniz