http://tjgig.com/karoushi_mycousin/

http://www.resonabank.co.jp/nenkin/info/economist/pdf/160325.pdf

http://yamagata-np.jp/news/201707/24/kj_2017072400549.php

https://www.kobe-np.co.jp/news/jiken/201707/0010412187.shtml

http://www3.nhk.or.jp/news/html/20170728/k10011078051000.html https://mainichi.jp/articles/20170728/k00/00e/040/251000c