http://www.sf.airnet.ne.jp/~ts/language/number.html

http://www.hermetic.ch/misc/numcol.htm

• links
  • http://wiscinfo.doit.wisc.edu/chaysimire/titulo2/khipus/what.htm
  • http://www.angelfire.com/mo/zdawg/Khipu/Khipu.html
• books
  • “Signs of the Inka Khipu, Binary Coding in the Andean Knotted-String Records” By Gary Urton http://www.utexas.edu/utpress/books/urtsig.html
  • online 'Databooks and How to Use Them' http://instruct1.cit.cornell.edu/research/quipu-ascher/contents.htm

“…articles and software concerning calendars, date conversion, encryption, factorization, prime numbers, cellular automata, C and HTML programming, lunar phases and eclipses and other scientific, business and computational topics.” http://www.hermetic.ch/

see also: Category Mathematics