@misc{Gill_David_Heliometer_1893,
 author={Gill, David},
 address={London},
 howpublished={online},
 year={1893},
 publisher={Eyre and Spottiswoode},
 language={eng},
 title={Heliometer observations for determination of stellar parallax},
 keywords={catalogue of stars, stellars parallaxes, Cape astronomical observatory},
}