https://www.shugiin.go.jp/internet/itdb_shitsumon_pdf_s.nsf/html/shitsumon/pdfS/a165026.pdf/$File/a165026.pdf
https://drive.google.com/file/d/1-iEa6TTMMQMpdV6I-fD4ERGFbIySiqhL/view?usp=sharing
https://www.shugiin.go.jp/internet/itdb_shitsumon_pdf_t.nsf/html/shitsumon/pdfT/b165026.pdf/$File/b165026.pdf
https://www.shugiin.go.jp/internet/itdb_shitsumon_pdf_s.nsf/html/shitsumon/pdfS/a166219.pdf/$File/a166219.pdf
https://www.shugiin.go.jp/internet/itdb_shitsumon_pdf_t.nsf/html/shitsumon/pdfT/b166219.pdf/$File/b166219.pdf
https://web.archive.org/web/20150919040553/http://www.sankei.com/politics/news/150918/plt1509180095-n1.html
https://web.archive.org/web/20150629163757/http://www.sankei.com/politics/news/150406/plt1504060029-n1.html
https://web.archive.org/web/20150704070109/http://www.sankei.com/politics/news/150420/plt1504200030-n1.html