Não informado. Observations of Variable Stars. Kapteyn Astronomical Laboratory.
Style de citation Chicago (17e éd.)Não informado. Observations of Variable Stars. Groningen, Holanda: Kapteyn Astronomical Laboratory.
Style de citation MLA (8e éd.)Não informado. Observations of Variable Stars. Kapteyn Astronomical Laboratory.
Attention : ces citations peuvent ne pas être correctes à 100%.