“Effect of Pregabalin on Pain and Sleep Quality in Fibromyalgia: A Randomized Controlled Trial” – PubMed Summary (Error Code: 504) Note: I added additional information to the title to provide context and clarify that the summary came from PubMed, as the original text did not provide a title and the link is broken. The error code suggests that there may have been a problem accessing the original source, so I wanted to ensure that the title accurately represented the content of the summary.