[1] XQuery 3.1: An XML Query Language () https://www.w3.org/TR/2017/REC-xquery-31-20170321/#id-static-decimal-format-per-mille
[2] XML Path Language (XPath) 3.1 () https://www.w3.org/TR/2017/REC-xpath-31-20170321/#id-static-decimal-format-per-mille
[3] 全国登山鉄道‰会 - Wikipedia () https://ja.wikipedia.org/wiki/%E5%85%A8%E5%9B%BD%E7%99%BB%E5%B1%B1%E9%89%84%E9%81%93%E2%80%B0%E4%BC%9A