The original paper which goes over the development of the Huth equation (please let me know if you actually mean something else) is by Heimo Huth:
Influence of Fastener Flexibility on the Prediction of Load Transfer and Fatigue Life for Multiple-Row Joints.
If you need the equation, reference the original, not the English translation.
Anyway, the Huth equation was developed based on extensive testing of joint specimens; the formula was derived to match the results. The paper describes the test specimen samples.
For single shear riveted joints, most of the specimens used appear to have been CSK according to Table 3 of the paper.
Huth's paper was made in response to what was seen as a lack of accurate data for fastener flexibility in aerospace applications and as a result, effort was made to test joints which might commonly be seen in analysis.
The Huth equation is valid for most joint configurations provided the proper Huth constants are used.
I suggest finding the paper and reading through it to determine if the formula will work for your situation.
Keep em' Flying
//Fight Corrosion!