Cita APA (7a ed.)

Pannekoek, A. (1913). The Variability of the Pole-star. s.n.

Cita Chicago Style (17a ed.)

Pannekoek, Anton. The Variability of the Pole-star. [S.l.: s.n, 1913.

Cita MLA (9a ed.)

Pannekoek, Anton. The Variability of the Pole-star. s.n, 1913.