I found in this paper (PDF) a mutual information between groups of variables such as these:
where F is a set of variables, and G is a set of sets of variables. I am neither statistician nor mathematician, but I have a fair knowledge about mutual information, and I do know how to calculate mutual information between two variables I(X;Y) if we have $n$ samples of X and Y. Can anyone help me do the same for the formulas above? Thanks.