I have been asked why I don't have links to the official webpages for all the cover artists who have provided art for my books. Usually, it's because I can't find them. In the case of Michael Herring I found a page for a different artist by that same name -- I've confirmed in e-mail that it's not the guy who did my cover.
I also found a musician, a broker, and others; it's a more common name than I had realized.
I didn't find the one I wanted, though -- probably because he quit the business. The best I could do was this Wiki entry. If you know of an official webpage for my cover artist, please e-mail me and let me know.