Não informado. Observations of Variable Stars. Kapteyn Astronomical Laboratory.
Chicagoスタイル(17版)引用形式Não informado. Observations of Variable Stars. Groningen, Holanda: Kapteyn Astronomical Laboratory.
MLA(8版)引用形式Não informado. Observations of Variable Stars. Kapteyn Astronomical Laboratory.
警告: この引用は必ずしも正確ではありません.