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?
I`m wondering if there is some kind of a general makroscopic thermodynamic or semiclassical argument (in analogy to some derivations of the first term) that motivates the appearance of the second logarithmic term and does not depend on how the microstates are quantum gravitationally implemented.