Matt Brown wrote:
"Cite your sources" is fine. "Provide your sources," though, is not. On many obscure topics, the sources WILL be difficult to locate. Any attempt to turn this requirement into having to provide sources that can be requested from the average library or online will remove a large number of very credible but obscure sources - specialist publications, limited circulation journals, and many other documents.
IMO, those would only be legitimate sources to cite if the subject itself is obscure and known only to specialists. If it's a well-known subject, it would make more sense to use mainstream sources on the subject. If the obscure source is indeed important, it will at least have been cited by someone else. If, for example, you find an obscure source on the Holocaust that is not cited in any mainstream work on the Holocaust, it would be original research to begin to build an argument based on it. (If you thought mainstream Holocaust historians were ignoring some obscure but credible and important source, that would be an issue to take up with them; we're just here to report the consensus in the field, not to create it.)
-Mark