I`ve just read, that for non extremal black holes, there exists a logarithmic (and other) correction(s) to the well known term proportional to the area of the horizon such that
$S = \frac{A}{4G} + K \ln \left(\frac{A}{4G}\right)$
where K is a constant.
How is this logarithmic (and other) correction term(s) derived generally? Or how can I see that there has to be such a logarithmic correction?
