Forum:CSS help

I've been editing the monobook skin, but can't find out how to refer to the 'wikia' section of the sidebar (where, for example, the toolbox is #p-tb). Also, how do I refer to external and interwiki links? I've read that it's a.external and a.extiw, but they don't seem to work. - Greenpickle(talk) 14:24, 2 April 2008 (UTC)