1. Knots: From combinatorics of knot diagrams to combinatorial topology based on knotshttp://arxiv.org/pdf/math/0703096.pdf
2. Celtic Art—The Methods of Construction;Bain,1973
3. Celtic Art in Pagan and Cristian Times;Allen,1904
4. Sona Geometry from Angola: Mathematics of an African Tradition;Gerdes,2006
5. Geometry from Africa: Mathematical and Educational Explorations;Gerdes,1999