Go to library. Search by author. Dickens, Charles. Open record. Click on book link at the top by the address bar! Show info captured.
JSTOR: Search for Mystery of Edwin Drood. Folder icon again. Click and select. Show in Zotero. Websites: Search for Mystery of Edwin Drood. You will see a folder icon. Click this and select editions. Show in Zotero. Google – go to third result (Google Books)