http://www.iseeker.org/blog/2007/12/10/gmail-%e6%90%9c%e7%b4%a2search%e5%92%8c%e8%bf%87%e6%bb%a4%e5%99%a8filter%e7%9a%84%e9%80%bb%e8%be%91%e8%bf%90%e7%ae%97boolean-operators/ Keep thinking, seeking and practicing! Wed, 03 Dec 2008 23:57:44 +0000 http://wordpress.org/?v=2.6