There is a wonderful 24 volume set of Swedish tunes, which is based on transcriptions from the turn of the last century (100+ years ago.) It was not available for a long time, but it was republished in 2000, a great resource at a very reasonable price, 3000 Swedish k., now at $366.09 US as of 1/22/2015.
http://translate.googleusercontent.com/ ... 77WHc6AavQ Svenska Låtar, by Nils Andersson, facimile of 1928 edition. Contains about 8000 tunes (a small portion of that available online at the website). This url points to English translation of the webpage.
There are many other interesting titles available here.