I understand that the MBTI is the most widely used test for assessing Jung's psychological types. However, I have read in this article and in this other article that there exist other instruments. Does anyone know anything about these tests? They seem to have been available at some point on a commercial basis, but are they still avaliable? A version of the first test seems to have been lost on this site, but I am not sure whether that was the final version or some earlier version.