ParadigmBusters Korean Volume 4 has recently been released. It's available on the Cheng & Tsui web site. I have previously been using the first 3 volumes first in a class and then for self study. I've been waiting for volume 4 for about a year, but it was worth the wait. These books are especially good for self study or supplemental study with whatever textbook your class might be using. Volume 4 would be considered Intermediate II. (I don't have any financial or even personal connection to anybody at ParadigmBusters, but their books are so good that I really want to recommend them to anybody looking for a good Korean textbook. Extremely useful.)
Good luck to everybody studying Korean!
