References
- 영부터 무한대까지 Reid;허민(역)
- Ganita-Bharati v.17 no.1-4 Who invented the zero Gupta, R.C.
- From one to zero: A universal history of numbers Ifrah, G.
- A universal history of numbers: From prehistory to the invention of the computer Ifrah, G.
- The nothing that is: a natural history of zero Kaplan, R.
- Discovery of zero and its impact on Indian mathematics Mukherjee, R.
- Internet J. Math. Ed. Sci. Tech. v.29 no.5 Much ado about nothing - an introductive inquiry about zero Pogliani, L.;M Randic;N Trinajstic