I am writing a paper where I examine information gain specifically with regards to feature selection and am wondering what the proper reference should be. I have looked all over and I can't find a good reference other than potentially referencing Shannon's original paper for entropy. It looks a little awkward in the paper since all of my other feature selection methods I mention I attribute to someone but I don't have one for information gain.
Edit: Put another way since apparently the above is hard to follow... I’m writing a paper, in my paper I use information gain and briefly describe it. I would like to know which paper to put in my references. For example if I talk about random forest I would say “we classify using random forest (Breiman, 2001)...” and then I would list Breiman’s paper in my references. Thing is (as I say in the question) I can’t find a paper where information gain is first introduced and so I don’t know what to cite and which author to attribute the method to.