Ahh, yes I see now that your website is doing parsing, and that linking up with another service to match, say, DOIs, would be a significant amount of additional work. Still, yours is a great tool!
You're probably already aware of it, but it might be worth checking out CrossRef's Simple Text Query
You're probably already aware of it, but it might be worth checking out CrossRef's Simple Text Query
http://www.crossref.org/SimpleTextQuery/