Just a suggestion, for gear submitted to an artist can a section or text entry fields be included for non-URL sources? Perhaps adhering to proper citation methods to avoid plagiarism? Examples could be the guitar/music magazines, and articles from within them. There is a huge amount of gear talk that is not online but printed and it is very hard to source when a URL cannot be provided.
Maybe having a few text fields for data entry that provides a template for proper citation and maybe having all fields required if text referencing is used. Example:
Author: John Smith Date/Month/Year Published: January 2015 Article Title: Artist´s Rig Talk Magazine/Book Title: A Guitar Magazine Issue/Volume Number: 200 Pages Used: 83-93
Just a thought.