Taiji Suzuki Masashi Sugiyama Jun Sese Takafumi Kanamori Approximating Mutual Information by Maximum Likelihood Density Ratio Estimation. 5-20 2008 4 Journal of Machine Learning Research - Proceedings Track http://www.jmlr.org/proceedings/papers/v4/suzuki08a.html db/journals/jmlr/jmlrp4.html#SuzukiSSK08