Não informado. (1921). Bulletin of the Astronomical Institutes of the Netherlands. Astronomical Institutes of the Netherlands.
Lua i Stíl Chicago (17ú heag.)Não informado. Bulletin of the Astronomical Institutes of the Netherlands. Amsterdam: Astronomical Institutes of the Netherlands, 1921.
Lua MLA (8ú heag.)Não informado. Bulletin of the Astronomical Institutes of the Netherlands. Astronomical Institutes of the Netherlands, 1921.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.