@misc{Gill_David_Zone_1923,
 author={Gill, David},
 address={London},
 howpublished={online},
 year={1923},
 publisher={His Majesty's Stationery Office},
 language={eng},
 title={Zone catalogue of 20,843 stars included between 40° and 52° of south declination, referred to the equinox 1900},
 keywords={catalogue of stars, zone -40° to -52°, the equinox 1900, Cape astronomical observatory},
}