If you are looking for more quotes on leadership Brainy Quotes has a page. I don't like the page much as you can't see the full quote but you might find some inspiration from it. To have a look at their quotes go to Leadership Quotes
If you are looking for a collection of quotes on leadership then I will be recommending a few sites and books. For sheer volume of good quotes on leadership I recommend the About.com page at the end of this post. The quotes are not listed in any particular order but there are some fantastic quotes and if you are looking for lots of choice I suggest you go and visit. Famous Leadership Quotes