@misc{Dyson_Frank_Watson_Astrographic_1921,
 author={Dyson, Frank Watson},
 address={Edinburgh},
 howpublished={online},
 year={1921},
 publisher={His Majesty's Stationery Office},
 language={eng},
 title={Astrographic Catalogue 1900.0 Greenwich Section Dec. +64° to +90°.},
 title={Vol. IV. Proper motions and photographic magnitudes},
 keywords={astrographic catalogue, star declination +64° to +90°, photographic magnitudes, Greenwich observatory},
}