Johnson, Dean R.H.; Soderblom, David R. (1987). “Calculating galactic space velocities and their uncertainties, with an application to the Ursa Major group”. Astronomical Journal. 93: 864. Bibcode:1987AJ.....93..864J. doi:10.1086/114370.
Johnson, Dean R.H.; Soderblom, David R. (1987). “Calculating galactic space velocities and their uncertainties, with an application to the Ursa Major group”. Astronomical Journal. 93: 864. Bibcode:1987AJ.....93..864J. doi:10.1086/114370.