I have used Serba Serbi Nusantara along with the other courses in the advanced package to review, refresh and strengthen my abilities in Indonesian after having lived outside of Indonesia for fifteen years. This course, in particular, added a ton to my vocabulary and helped me with reading and listening skills. The use of genuine materials makes this one of the best ways to grow in language learning and also deepen cultural understanding. My only suggestion is that the creators go back and check on a few of the lessons in this and their other courses for small errors. Here and there we find questions in one lesson that refer to another or other little glitches. Still, the advanced package with several courses is a great value for the money and the best self-study material I’ve ever seen.