Yeager, K. E.; et al. (January 2011). "On the ejection of Earth-mass planets from the habitable zones of the solar twins HD 20782 and HD 188015". International Journal of Astrobiology. 10 (1): 1–13. Bibcode:2011IJAsB..10....1Y. doi:10.1017/S1473550410000145. S2CID119625844.
Heard, John Frederick (1956). "The radial velocities, spectral classes and photographic magnitudes of 1041 late-type stars". Publications of the David Dunlap Observatory. 2 (4). University of Toronto, Toronto, Canada: University of Toronto Press: 107–143. Bibcode:1956PDDO....2..107H.
Yeager, K. E.; et al. (January 2011). "On the ejection of Earth-mass planets from the habitable zones of the solar twins HD 20782 and HD 188015". International Journal of Astrobiology. 10 (1): 1–13. Bibcode:2011IJAsB..10....1Y. doi:10.1017/S1473550410000145. S2CID119625844.
Yeager, K. E.; et al. (January 2011). "On the ejection of Earth-mass planets from the habitable zones of the solar twins HD 20782 and HD 188015". International Journal of Astrobiology. 10 (1): 1–13. Bibcode:2011IJAsB..10....1Y. doi:10.1017/S1473550410000145. S2CID119625844.