I have found the following books to be excellent references for research on edged weapons types, identification, history and ethnography.  Some contain errors, and this is most common in the earliest published.  As in most intellectual endeavors, it is wise to find multiple sources of ideas and expertise.  The books are listed in relevant categories shown on the left.  If you buy the book from here, I get a small payment that goes entirely to the upkeep of this website.  Thank you!