Cita APA (7th ed.)
Harkness, W. (1891). The Solar Parallax and its related constants.
Cita Chicago (17th ed.)
Harkness, William. The Solar Parallax and Its Related Constants. Washington, 1891.
Cita MLA (9th ed.)
Harkness, William. The Solar Parallax and Its Related Constants. 1891.
Atenció: Aquestes cites poden no estar 100% correctes.