[1] [CITE@en[U+030A COMBINING RING ABOVE (̊) - Charinfo]]
([TIME[2016-12-31 10:58:21 +09:00]])
<https://chars.suikawiki.org/char/030A>

- [164] [CITE[The Unicode Standard, Version 13.0 - ch07.pdf]], [TIME[2020-03-09T17:53:38.000Z]], [TIME[2020-12-07T09:15:13.901Z]] <https://www.unicode.org/versions/latest/ch07.pdf#M9.37081.HeadingBreak.79.Combining.Marks>