Hoffmann 2024. Hoffmann, Friedhelm (2024-03-11). "Aspects of Zero in Ancient Egypt". In Gobets, Peter; Lawrence Kuhn, Robert (eds.). The Origin and Significance of Zero: An Interdisciplinary Perspective. Brill. pp. 64–81. doi:10.1163/9789004691568_007. ISBN978-90-04-69156-8.
st-andrews.ac.uk
mathshistory.st-andrews.ac.uk
"Egyptian numerals". MacTutor - School of Mathematics and Statistics. University of St. Andrews. Retrieved January 12, 2023.