http://www.eyedeal.co.jp/technology/robustestimation.html
http://imagingsolution.blog107.fc2.com/blog-entry-32.html
http://www23.atwiki.jp/yahirohumpty/pages/5.html
http://cl-www.msi.co.jp/reports/robust.html
http://sonickun.hatenablog.com/entry/2015/01/19/232916
http://www.cybernet.co.jp/maple/documents/pdf/example/math/RobustEstimation.pdf
http://www.nakl.t.u-tokyo.ac.jp/~masuda/papers/smt09as.pdf