Welcome to Wikipedia. Everyone is welcome to contribute to the encyclopedia, but when you add or change content, as you did to the article Prime number, please cite a reliable source for the content of your edit. This helps maintain our policy of verifiability. Take a look at Wikipedia:Citing sources for information about how to cite sources and the welcome page to learn more about contributing to this encyclopedia. Thank you. Favonian ( talk) 17:19, 1 September 2010 (UTC) reply