*Citation Machine: http://citationmachine.net/
The information involved in a citation comes from a database. Hence, if there is no information in the database, you must use manual entry. Citation Machine just simply gets the format, plugs in the information, and then displays it for you to copy and paste. Citation Machine uses ISBN numbers to query their database, the authors have not, as of yet, found an ISBN number which exists in the Citation Machine database.<br>
*Xpert: http://www.nottingham.ac.uk/xpert/attribution/
This site also uses a database. However, they explicitly offer the usage of their current database, which means they might also offer knowledge on how they've created the attibution information on individual resources.
*CC Metadata Humanizer: http://code.creativecommons.org/~john/ Queries for, but does not seem to find, CC relevant metadata. <br> *OCW cite/attribute: http://ocw.korea.edu/ocw Uses a simple JS prompt for its own attribution information (was there a tool here? I didn't find it) *Wikimedia Commons: http://commons.wikimedia.org The Wikimedia Commons offers an API for pulling an XML of the metadata included in a document. This API must be implemented and queried to pull the attribution information.<br>
*Wikipedia citation tools: http://en.wikipedia.org/wiki/Wikipedia:Citation_tools