The number zero was invented twice - once in India and once in Mesoamerica. This invention is considered especially significant because it required a considerable cognitive leap to achieve and because it opened the door to a host of new applications for numbers.
- Bourbaki, Nicolas. Elements of the History of Mathematics (1998) - can be found (in limited form) on Google Books
- Kaplan, Robert. The Nothing that is: A Natural History of Zero (1999) - can be found (in limited form) on Google Books
- Seife, Charles. Zero: The Biography of a Dangerous Idea (2000) - can be found (in limited form) on Google Books