[1] [CITE@ja[世界の文字]]
([TIME[2020-08-04T15:52:59.000Z]], [TIME[2020-10-24T08:15:31.975Z]])
<https://www.chikyukotobamura.org/muse/wr_europa_11.html>

[2] [CITE[IR208cv.PDF - 208.pdf]], [TIME[2022-11-02T03:16:36.000Z]], [TIME[2022-12-10T06:00:10.383Z]] <https://itscj.ipsj.or.jp/ir/208.pdf>