For Korean coins (old and contemporary), I find the Dae Gwang Sa Catalogue to be useful. The text is mostly written in Korean, but there are some (poorly translated!) English explanations in it, too. You can find the Dae Gwang Sa Catalogue at Ebay, just search "Korean coin catalogue", and you'll probably be looking at a Dae Gwang Sa Catalogue. I have a comparison chart at the bottom of one of my webpages that compares Krause values to Dae Gwang Sa values. Very interesting indeed: http://www.dokdo-research.com/koreancoins.html What Korean coin collectors still need is a GRADING REFERENCE of some kind, especially for the coins I collect: The contemporary coins (1966-Date). It would also be nice to know the average condition of certain coins, and how many actually exist (populations), etc. but I don't think that there is a large enough of a collecting community for that to happen(?), or there just aren't enough "geeks" out there to do that work.