https://miningoo.com/483
https://miningoo.com/474
http://qiita.com/grachro/items/11e59d16a929d27e274e
https://ja.wikipedia.org/wiki/Wikipedia:%E3%83%87%E3%83%BC%E3%82%BF%E3%83%99%E3%83%BC%E3%82%B9%E3%83%80%E3%82%A6%E3%83%B3%E3%83%AD%E3%83%BC%E3%83%89
https://dumps.wikimedia.org/jawiki/latest/