marking up quotation types

Hello, 

I run quotationsbook.com. We've made very sincere efforts to promote a distinct type for a quote, or a citation. Effectively, a quote can be seen as a statement made by a person or entity, and it has great wider implications for any citation marked up anywhere, on a blog post, web page, book, or otherwise.

By it's nature, a quote is short (whatever that is defined as) - so entire books/essays are not quotable. It doesn't quite fit article, news or book content types.

Our existing structured data efforts are available to syndicate freely here:
http://quotationsbook.com/services/

We initially went for Google Base, then a different sort of markup. Subsequently, I looked at Google Rich Snippets, and found there was no way to markup a quote that was dedicated. We also contributed all our content to Freebase under a C-C license.

So - I need some help. Is there any neat schema within schema.org that fits a quote? Can someone help me create one that is agreed upon by all search engines?

thanks
Amit
http://quotationsbook.com/about/
http://amitkoth.com