Não informado. (1921). Bulletin of the Astronomical Institutes of the Netherlands. Astronomical Institutes of the Netherlands.
Chicagoスタイル(17版)引用形式Não informado. Bulletin of the Astronomical Institutes of the Netherlands. Amsterdam: Astronomical Institutes of the Netherlands, 1921.
MLA(8版)引用形式Não informado. Bulletin of the Astronomical Institutes of the Netherlands. Astronomical Institutes of the Netherlands, 1921.
警告: この引用は必ずしも正確ではありません.